Commit Graph

916 Commits (a79b4b31c9cd60d1b46882ec8fc7c0c97237682c)

Author SHA1 Message Date
eaydingol a79b4b31c9 Improve lateral check and add test cases 2025-08-16 00:08:50 +03:00
eaydingol a964d45323 Update comments, checks 2025-08-16 00:08:50 +03:00
eaydingol 13405e7871 Run update quals code only for queries with outer joins, update planners for error handling, update test cases. 2025-08-16 00:08:50 +03:00
eaydingol 0cf34388e2 Update test cases w.r.to 8113 2025-08-16 00:08:50 +03:00
eaydingol efbf6a7bc2 Fix test dependencies 2025-08-16 00:08:50 +03:00
eaydingol e58d730e64 Extend the logic to right joins 2025-08-16 00:08:50 +03:00
eaydingol 49d163fb63 Update test cases 2025-08-16 00:08:50 +03:00
eaydingol 4f618a355d Disable recurring/non-recurring outer join push down for lateral joins, update test cases 2025-08-16 00:08:50 +03:00
eaydingol a850c3e3a5 Refactor the update part 2025-08-16 00:08:50 +03:00
eaydingol 7a89dad904 Fix task computation 2025-08-16 00:08:50 +03:00
eaydingol 188043c5e7 Add a guc for the feature 2025-08-16 00:08:50 +03:00
eaydingol fc109f408b reindent 2025-08-16 00:08:50 +03:00
eaydingol afd3bd921d Revert ununsed helper functions after refactor 2025-08-16 00:08:50 +03:00
eaydingol 9f72067c12 Use quals for both on and using syntax. 2025-08-16 00:08:50 +03:00
eaydingol 96a7d70fa9 update tests 2025-08-16 00:08:50 +03:00
eaydingol cd9f6ae313 Enable push down only for reference table 2025-08-16 00:08:50 +03:00
eaydingol c08c1eb299 Introduce a method to check if the left join is safe to push-down, use the same method to compute constraints for push 2025-08-16 00:08:50 +03:00
eaydingol 1060de98d3 Refactor the code, add checks for the join clause, add basic test cases. 2025-08-16 00:08:50 +03:00
eaydingol fccc4324a6 Check if the outer table has distribution column, wip, still need to check the using clause or join constraint 2025-08-16 00:08:50 +03:00
eaydingol f42c8edd43 list case 2025-08-16 00:08:50 +03:00
eaydingol ef362f403b Do not push down the left join for nested cases. 2025-08-16 00:08:50 +03:00
eaydingol 5e57908f5b Check outer entry in left join. 2025-08-16 00:08:50 +03:00
eaydingol 53f2506901 push down left join, wip 2025-08-16 00:08:50 +03:00
Mehmet YILMAZ a6161f5a21
Fix CTE traversal for outer Vars in FindReferencedTableColumn (remove assert; correct parentQueryList handling) (#8106)
fixes #8105 

This change lets `FindReferencedTableColumn()` correctly resolve columns
through a CTE even when the expression comes from an outer query level
(`varlevelsup > 0`, `skipOuterVars = false`). Before, we hit an
`Assert(skipOuterVars)` in this path.

**Problem**

* Hitting a CTE after walking outer Vars triggered
`Assert(skipOuterVars)`.
* Cause: we modified `parentQueryList` in place and didn’t rebuild the
correct parent chain before recursing into the CTE, so the path was
considered unsafe.

**Fix**

* Remove the `Assert(skipOuterVars)` in the `RTE_CTE` branch.
* Find the CTE’s owning level via `ctelevelsup` and compute
`cteParentListIndex`.
* Rebuild a private parent list for recursion: `list_copy` →
`list_truncate` → `lappend(current query)`.
* Add a bounds check before indexing the CTE’s `targetList`.

**Why it works**


```diff
-parentQueryList = lappend(parentQueryList, query);
-FindReferencedTableColumn(targetEntry->expr, parentQueryList,
-                          cteQuery, column, rteContainingReferencedColumn,
-                          skipOuterVars);
+    /* hand a private, bounded parent list to the recursion */
+    List *newParent = list_copy(parentQueryList);
+    newParent = list_truncate(newParent, cteParentListIndex + 1);
+    newParent = lappend(newParent, query);
+
+    FindReferencedTableColumn(targetEntry->expr,
+                              newParent,
+                              cteQuery,
+                              column,
+                              rteContainingReferencedColumn,
+                              skipOuterVars);
+}


```
**Before:** We changed `parentQueryList` in place (`parentQueryList =
lappend(...)`) and didn’t trim it to the CTE’s owner level.

**After:** We copy the list, trim it to the CTE’s owner level, then
append the current query. This keeps the parent list accurate for the
current recursion and safe when following outer Vars.


**Example: Nested subquery referencing the CTE (two levels down)**

```
WITH c AS MATERIALIZED (SELECT user_id FROM raw_events_first)
SELECT 1
FROM raw_events_first t
WHERE EXISTS (
  SELECT 1
  FROM (SELECT user_id FROM c) c2
  WHERE c2.user_id = t.user_id
);
```

Levels:
Q0 = top SELECT
Q1 = EXISTS subquery
Q2 = inner (SELECT user_id FROM c)

When resolving c2.user_id inside Q2:

- parentQueryList is [Q0, Q1, Q2].
- `ctelevelsup`: 2


`cteParentListIndex = length(parentQueryList) - ctelevelsup - 1`

- Recurse into the CTE’s query with [Q0, Q2].


**Tests (added in `multi_insert_select`)**

* **T1:** Correlated subquery that references a CTE (one level down) 
Verifies that resolving through `RTE_CTE` after following an outer `Var`
succeeds, row count matches source table.
* **T2:** Nested subquery that references a CTE (two levels down) 
Exercises deeper recursion and confirms identical to T1.
* **T3:** Scalar subquery in a target list that reads from the outer CTE
Checks expected row count and that no NULLs are inserted.

These tests cover the cases that previously hit `Assert(skipOuterVars)`
and confirm CTE references while following outer Vars.
2025-08-12 11:49:50 +03:00
eaydingol 3d8fd337e5
Check outer table partition column (#8092)
DESCRIPTION: Introduce a new check to push down a query including union
and outer join to fix #8091 .

In "SafeToPushdownUnionSubquery", we check if the distribution column of
the outer relation is in the target list.
2025-08-06 16:13:14 +03:00
Teja Mupparti 889aa92ac0
EXPLAIN ANALYZE - Prevent execution of the plan during the plan-print (#8017)
DESCRIPTION: Fixed a bug in EXPLAIN ANALYZE to prevent unintended (duplicate) execution of the (sub)plans during the explain phase.

Fixes #4212 

### 🐞 Bug #4212 : Redundant (Subplan) Execution in `EXPLAIN ANALYZE`
codepath

#### 🔍 Background
In the standard PostgreSQL execution path, `ExplainOnePlan()` is
responsible for two distinct operations depending on whether `EXPLAIN
ANALYZE` is requested:

1. **Execute the plan**

   ```c
   if (es->analyze)
       ExecutorRun(queryDesc, direction, 0L, true);
   ```

2. **Print the plan tree** 

   ```c
   ExplainPrintPlan(es, queryDesc);
   ```

When printing the plan, the executor should **not run the plan again**.
Execution is only expected to happen once—at the top level when
`es->analyze = true`.

---

#### ⚠️ Issue in Citus

In the Citus implementation of `CustomScanMethods.ExplainCustomScan =
CitusExplainScan`, which is a custom scan explain callback function used
to print explain information of a Citus plan incorrectly performs
**redundant execution** inside the explain path of `ExplainPrintPlan()`

```c
ExplainOnePlan()
  ExplainPrintPlan()
      ExplainNode()
        CitusExplainScan()
          if (distributedPlan->subPlanList != NIL)
          {
              ExplainSubPlans(distributedPlan, es);
             {
              PlannedStmt *plan = subPlan->plan;
              ExplainOnePlan(plan, ...);  // ⚠️ May re-execute subplan if es->analyze is true
             }
         }
```
This causes the subplans to be **executed again**, even though they have
already been executed during the top-level plan execution. This behavior
violates the expectation in PostgreSQL where `EXPLAIN ANALYZE` should
**execute each node exactly once** for analysis.

---
####  Fix (proposed)
Save the output of Subplans during `ExecuteSubPlans()`, and later use it
in `ExplainSubPlans()`
2025-07-30 11:29:50 -07:00
Colm f1160b0892
Fix assert failure introduced in 245a62df3e
The assert on the number of shards incorrectly used the value of
citus.shard_replication_factor; it should check the table's metadata
to determine the replication factor of its data, and not assume it is
the current GUC value.
2025-07-24 16:19:39 +03:00
Mehmet YILMAZ 9327df8446
Add PG 18Beta2 Build compatibility (#8060)
Fixes #8061 

Add PG 18Beta2 Build compatibility

Revert "Don't lock partitions pruned by initial pruning
Relevant PG commit:
1722d5eb05d8e5d2e064cd1798abcae4f296ca9d
https://github.com/postgres/postgres/commit/1722d5e
2025-07-23 15:15:55 +03:00
Colm 9ccf758bb8
Fix PG15 compiler error introduced in commit 245a62df3e (#8069)
Commit 245a62df3e included an assertion on a struct field that is
in PG16+, without PG_VERSION_NUM check. This commit removes the
offending line of code. The same assertion is present later in the
function with the PG_VERSION_NUM check, so the offending line of code is
redundant.
2025-07-23 10:44:26 +01:00
Colm 245a62df3e
Avoid query deparse and planning of shard query in local execution. (#8035)
DESCRIPTION: Avoid query deparse and planning of shard query in local execution. Adds citus.enable_local_execution_local_plan GUC to allow avoiding unnecessary query deparsing to improve performance of fast-path queries targeting local shards.

If a fast path query resolves to a shard that is local to the node planning the query, a shortcut can be taken so that the OID of the shard is plugged into the parse tree, which is then planned by Postgres. In `local_executor.c` the task uses that plan instead of parsing and planning a shard query. How this is done: The fast path planner identifies if the shortcut is possible, and then the distributed planner checks, using `CheckAndBuildDelayedFastPathPlan()`, if a local plan can be generated or if the shard query should be generated.

This optimization is controlled by a GUC `citus.enable_local_execution_local_plan` which is on by default. A new
regress test `local_execution_local_plan` tests both row-sharding and schema sharding. Negative tests are added to
`local_shard_execution_dropped_column` to verify that the optimization is not taken when the shard is local but there is a difference between the shard and distributed table because of a dropped column.
2025-07-22 17:16:53 +01:00
Mehmet YILMAZ 5005be31e6
PG18 - Handle PG18’s synthetic `RTE_GROUP` in `FindReferencedTableColumn` for correct GROUP BY pushdown (#8034)
Fixes #8032 

PostgreSQL 18 introduces a dedicated “grouping-step” range table entry
(`RTE_GROUP`) whose target columns are exactly the expressions in our
`GROUP BY` clause, rather than hiding them as `resjunk` items. In
Citus’s distributed planner, the function `FindReferencedTableColumn`
must be able to map from a `Var` referencing a grouped column back to
the underlying table column. Without special handling for `RTE_GROUP`,
queries that rely on pushdown of `GROUP BY` expressions can fail or
mis-identify their target columns.

This PR adds support for `RTE_GROUP` in Citus when built against PG 18
or later, ensuring that:

* Each grouped expression is correctly resolved.
* The pushdown planner can trace a `Var`’s `varattno` into the
corresponding `groupexprs` list.
* Existing behavior on PG < 18 is unchanged.

---

## What’s Changed

In **`src/backend/distributed/planner/multi_logical_optimizer.c`**,
inside `FindReferencedTableColumn`:

* **Under** `#if PG_VERSION_NUM >= PG_VERSION_18`
  Introduce an `else if` branch for

  ```c
  rangeTableEntry->rtekind == RTE_GROUP
  ```

* **Extraction of grouped expressions:**

  ```c
  List *groupexprs   = rangeTableEntry->groupexprs;
  AttrNumber groupIndex = candidateColumn->varattno - 1;
  ```

* **Safety check** to guard against malformed `Var` numbers:

  ```c
  if (groupIndex < 0 || groupIndex >= list_length(groupexprs))
      return;    /* malformed Var */
  ```

* **Recursive descent:**
  Fetch the corresponding expression from `groupexprs` and call

  ```c
  FindReferencedTableColumn(groupExpr, parentQueryList, query,
                            column, rteContainingReferencedColumn,
                            skipOuterVars);
  ```

so that the normal resolution logic applies to the underlying
expression.

* **Unchanged code path** for PG < 18 and for other `rtekind` values.

---
2025-07-16 23:23:14 +03:00
Mehmet YILMAZ 9e42f3f2c4
Add PG 18Beta1 compatibility (Build + RuleUtils) (#7981)
This PR provides successful build against PG18Beta1. RuleUtils PR was
reviewed separately: #8010

## PG 18Beta1–related changes for building Citus


### TupleDesc / Attr layout

**What changed in PG:** Postgres consolidated the
`TupleDescData.attrs[]` array into a more compact representation. Direct
field access (tupdesc->attrs[i]) was replaced by the new
`TupleDescAttr()` API.

**Citus adaptation:** Everywhere we previously used
`tupdesc->attrs[...]`, we now call `TupleDescAttr(tupdesc, idx)` (or our
own `Attr()` macro) under a compatibility guard.
*
5983a4cffc

General Logic:

* Use `Attr(...)` in places where `columnar_version_compat.h` is
included. This avoids the need to sprinkle `#if PG_VERSION_NUM` guards
around each attribute access.

* Use `TupleDescAttr(tupdesc, i)` when the relevant PostgreSQL header is
already included and the additional macro indirection is unnecessary.


### Collation‐aware `LIKE`

**What changed in PG:** The `textlike` operator now requires an explicit
collation, to avoid ambiguous‐collation errors. Core code switched from
`DirectFunctionCall2(textlike, ...)` to
`DirectFunctionCall2Coll(textlike, DEFAULT_COLLATION_OID, ...)`.

**Citus adaptation:** In `remote_commands.c` and any other LIKE call, we
now use `DirectFunctionCall2Coll(textlike, DEFAULT_COLLATION_OID, ...)`
and `#include <utils/pg_collation.h>`.

*
85b7efa1cd

### Columnar storage API

* Adapt `columnar_relation_set_new_filelocator` (and related init
routines) for PG 18’s revised SMGR and storage-initialization hooks.
* Pull in the new headers (`explain_format.h`,
`columnar_version_compat.h`) so the columnar module compiles cleanly
against PG 18.
- heap_modify_tuple + heap_inplace_update only exist on PG < 18; on PG18
the in-place helper was removed upstream


-
a07e03fd8f

### OpenSSL / TLS integration

**What changed in PG:** Moved from the legacy `SSL_library_init()` to
`OPENSSL_init_ssl(OPENSSL_INIT_LOAD_CONFIG, NULL)`, updated certificate
API calls (`X509_getm_notBefore`, `X509_getm_notAfter`), and
standardized on `TLS_method()`.

**Citus adaptation:** We now `#include <openssl/opensslv.h>` and use
`#if OPENSSL_VERSION_NUMBER >= 0x10100000L` to choose between`
OPENSSL_init_ssl()` or `SSL_library_init()`, and wrap`
X509_gmtime_adj()` calls around the new accessor functions.

*
6c66b7443c


### Adapt `ExtractColumns()` to the new PG-18 `expandRTE()` signature

PostgreSQL 18
80feb727c8
added a fourth argument of type `VarReturningType` to `expandRTE()`, so
calls that used the old 7-parameter form no longer compile. This patch:

* Wraps the `expandRTE(...)` call in a `#if PG_VERSION_NUM >= 180000`
guard.
* On PG 18+ passes the new `VAR_RETURNING_DEFAULT` argument before
`location`.
* On PG 15–17 continues to call the original 7-arg form.
* Adds the necessary includes (`parser/parse_relation.h` for `expandRTE`
and `VarReturningType`, and `pg_version_constants.h` for
`PG_VERSION_NUM`).



### Adapt `ExecutorStart`/`ExecutorRun` hooks to PG-18’s new signatures

PostgreSQL 18
525392d572
changed the signatures of the executor hooks:

* `ExecutorStart_hook` now returns `bool` instead of `void`, and
* `ExecutorRun_hook` drops its old `run_once` argument.

This patch preserves Citus’s existing hook logic by:

1. **Adding two adapter functions** under `#if PG_VERSION_NUM >=
PG_VERSION_18`:

   * `citus_executor_start_adapter(QueryDesc *queryDesc, int eflags)`
Calls the old `CitusExecutorStart(queryDesc, eflags)` and then returns
`true` to satisfy the new hook’s `bool` return type.
* `citus_executor_run_adapter(QueryDesc *queryDesc, ScanDirection
direction, uint64 count)`
Calls the old `CitusExecutorRun(queryDesc, direction, count, true)`
(passing `true` for the dropped `run_once` argument), and returns
`void`.

2. **Installing the adapters** in `_PG_init()` instead of the original
hooks when building against PG 18+:

   ```c
   #if PG_VERSION_NUM >= PG_VERSION_18
       ExecutorStart_hook = citus_executor_start_adapter;
       ExecutorRun_hook   = citus_executor_run_adapter;
   #else
       ExecutorStart_hook = CitusExecutorStart;
       ExecutorRun_hook   = CitusExecutorRun;
   #endif
   ```
   
### Adapt to PG-18’s removal of the “run\_once” flag from
ExecutorRun/PortalRun

PostgreSQL commit
[[3eea7a0](3eea7a0c97)
rationalized the executor’s parallelism logic by moving the “execute a
plan only once” check into `ExecutePlan()` itself and dropping the old
`bool run_once` argument from the public APIs:

```diff
- void ExecutorRun(QueryDesc *queryDesc,
-                  ScanDirection direction,
-                  uint64 count,
-                  bool run_once);
+ void ExecutorRun(QueryDesc *queryDesc,
+                  ScanDirection direction,
+                  uint64 count);
```

(and similarly for `PortalRun()`).

To stay compatible across PG 15–18, Citus now:

1. **Updates all internal calls** to `ExecutorRun(...)` and
`PortalRun(...)`:

* On PG 18+, use the new three-argument form (`ExecutorRun(qd, dir,
count)`).
* On PG 15–17, keep the old four-arg form (`ExecutorRun(qd, dir, count,
true)`) under a `#if PG_VERSION_NUM < 180000` guard.

2. **Guards the dispatcher hooks** via the adapter functions (from the
earlier patch) so that Citus’s executor hooks continue to work under
both the old and new signatures.


### Adapt to PG-18’s shortened PortalRun signature

PostgreSQL 18’s refactoring (see commit
[3eea7a0](3eea7a0c97))
also removed the old run_once and alternate‐dest arguments from the
public PortalRun() API. The signature changed from:



```diff
- bool PortalRun(Portal portal,
-                long count,
-                bool isTopLevel,
-                bool run_once,
-                DestReceiver *dest,
-                DestReceiver *altdest,
-                QueryCompletion *qc);
+ bool PortalRun(Portal portal,
+                long count,
+                bool isTopLevel,
+                DestReceiver *dest,
+                DestReceiver *altdest,
+                QueryCompletion *qc);
```

To support both versions in Citus, we:

1. **Version-guard each call** to `PortalRun()`:

   * **On PG 18+** invoke the new 6-argument form.
* **On PG 15–17** fall back to the legacy 7-argument form, passing
`true` for `run_once`.
   
### Add support for PG-18’s new `plansource` argument in
`PortalDefineQuery`**

PostgreSQL 18 extended the `PortalDefineQuery` API to carry a
`CachedPlanSource *plansource` pointer so that the portal machinery can
track cached‐plan invalidation (as introduced alongside deferred-locking
in commit
525392d572.
To remain compatible across PG 15–18, Citus now wraps its calls under a
version guard:

```diff
-   PortalDefineQuery(portal, NULL, sql, commandTag, plantree_list, NULL);
+#if PG_VERSION_NUM >= 180000
+   /* PG 18+: seven-arg signature (adds plansource) */
+   PortalDefineQuery(
+       portal,
+       NULL,            /* no prepared-stmt name */
+       sql,             /* the query text */
+       commandTag,      /* the CommandTag */
+       plantree_list,   /* List of PlannedStmt* */
+       NULL,            /* no CachedPlan */
+       NULL             /* no CachedPlanSource */
+   );
+#else
+   /* PG 15–17: six-arg signature */
+   PortalDefineQuery(
+       portal,
+       NULL,            /* no prepared-stmt name */
+       sql,             /* the query text */
+       commandTag,      /* the CommandTag */
+       plantree_list,   /* List of PlannedStmt* */
+       NULL             /* no CachedPlan */
+   );
+#endif
```


### Adapt ExecInitRangeTable() calls to PG-18’s new signature

PostgreSQL commit
[cbc127917e04a978a788b8bc9d35a70244396d5b](cbc127917e)
overhauled the planner API for range‐table initialization:

**PG 18+**: added a fourth `Bitmapset *unpruned_relids` argument to
support deferred partition pruning

In Citus’s `create_estate_for_relation()` (in `columnar_metadata.c`), we
now wrap the call in a compile‐time guard so that the code compiles
correctly on all supported PostgreSQL versions:

```
/* Prepare permission info on PG 16+ */
#if PG_VERSION_NUM >= PG_VERSION_16
    List *perminfos = NIL;
    addRTEPermissionInfo(&perminfos, rte);
#else
    List *perminfos = NIL;  /* unused on PG 15 */
#endif

/* Initialize the range table, with the right signature for each PG version */
#if PG_VERSION_NUM >= PG_VERSION_18
    /* PG 18+: four‐arg signature (adds unpruned_relids) */
    ExecInitRangeTable(
        estate,
        list_make1(rte),
        perminfos,
        NULL        /* unpruned_relids: not used by columnar */
    );
#elif PG_VERSION_NUM >= PG_VERSION_16
    /* PG 16–17: three‐arg signature (permInfos) */
    ExecInitRangeTable(
        estate,
        list_make1(rte),
        perminfos
    );
#else
    /* PG 15: two‐arg signature */
    ExecInitRangeTable(
        estate,
        list_make1(rte)
    );
#endif

estate->es_output_cid = GetCurrentCommandId(true);
```

### Adapt `pgstat_report_vacuum()` to PG-18’s new timestamp argument

PostgreSQL commit
[[30a6ed0ce4bb18212ec38cdb537ea4b43bc99b83](30a6ed0ce4)
extended the `pgstat_report_vacuum()` API by adding a `TimestampTz
start_time` parameter at the end so that the VACUUM statistics collector
can record when the operation began:

```diff
/* PG ≤17: four-arg signature */
- void pgstat_report_vacuum(Oid tableoid,
-                           bool shared,
-                           double num_live_tuples,
-                           double num_dead_tuples);
+/* PG ≥18: five-arg signature adds a start_time */
+ void pgstat_report_vacuum(Oid tableoid,
+                           bool shared,
+                           double num_live_tuples,
+                           double num_dead_tuples,
+                           TimestampTz start_time);
```

To support both versions, we now wrap the call in `columnar_tableam.c`
with a version guard, supplying `GetCurrentTimestamp()` for PG-18+:

```c
#if PG_VERSION_NUM >= 180000
    /* PG 18+: include start_timestamp */
    pgstat_report_vacuum(
        RelationGetRelid(rel),
        rel->rd_rel->relisshared,
        Max(new_live_tuples, 0),  /* live tuples */
        0,                        /* dead tuples */
        GetCurrentTimestamp()     /* start time */
    );
#else
    /* PG 15–17: original signature */
    pgstat_report_vacuum(
        RelationGetRelid(rel),
        rel->rd_rel->relisshared,
        Max(new_live_tuples, 0),  /* live tuples */
        0                         /* dead tuples */
    );
#endif
```


### Adapt `ExecuteTaskPlan()` to PG-18’s expanded `CreateQueryDesc()`
signature

PostgreSQL 18 changed `CreateQueryDesc()` from an eight-argument to a
nine-argument call by inserting a `CachedPlan *cplan` parameter
immediately after the `PlannedStmt *plannedstmt` argument (see commit
525392d572).
To remain compatible with PG 15–17, Citus now wraps its invocation in
`local_executor.c` with a version guard:

```diff
-    /* PG15–17: eight-arg CreateQueryDesc without cached plan */
-    QueryDesc *queryDesc = CreateQueryDesc(
-        taskPlan,           /* PlannedStmt *plannedstmt */
-        queryString,        /* const char *sourceText */
-        GetActiveSnapshot(),/* Snapshot snapshot */
-        InvalidSnapshot,    /* Snapshot crosscheck_snapshot */
-        destReceiver,       /* DestReceiver *dest */
-        paramListInfo,      /* ParamListInfo params */
-        queryEnv,           /* QueryEnvironment *queryEnv */
-        0                   /* int instrument_options */
-    );
+#if PG_VERSION_NUM >= 180000
+    /* PG18+: nine-arg CreateQueryDesc with a CachedPlan slot */
+    QueryDesc *queryDesc = CreateQueryDesc(
+        taskPlan,           /* PlannedStmt *plannedstmt */
+        NULL,               /* CachedPlan *cplan (none) */
+        queryString,        /* const char *sourceText */
+        GetActiveSnapshot(),/* Snapshot snapshot */
+        InvalidSnapshot,    /* Snapshot crosscheck_snapshot */
+        destReceiver,       /* DestReceiver *dest */
+        paramListInfo,      /* ParamListInfo params */
+        queryEnv,           /* QueryEnvironment *queryEnv */
+        0                   /* int instrument_options */
+    );
+#else
+    /* PG15–17: eight-arg CreateQueryDesc without cached plan */
+    QueryDesc *queryDesc = CreateQueryDesc(
+        taskPlan,           /* PlannedStmt *plannedstmt */
+        queryString,        /* const char *sourceText */
+        GetActiveSnapshot(),/* Snapshot snapshot */
+        InvalidSnapshot,    /* Snapshot crosscheck_snapshot */
+        destReceiver,       /* DestReceiver *dest */
+        paramListInfo,      /* ParamListInfo params */
+        queryEnv,           /* QueryEnvironment *queryEnv */
+        0                   /* int instrument_options */
+    );
+#endif
```



### Adapt `RelationGetPrimaryKeyIndex()` to PG-18’s new “deferrable\_ok”
flag

PostgreSQL commit
14e87ffa5c
added a new Boolean `deferrable_ok` parameter to
`RelationGetPrimaryKeyIndex()` so that the lock manager can defer
unique‐constraint locks when requested. The API changed from:

```c
RelationGetPrimaryKeyIndex(Relation relation)
```

to:

```c
RelationGetPrimaryKeyIndex(Relation relation, bool deferrable_ok)
 ```
                
```diff
diff --git a/src/backend/distributed/metadata/node_metadata.c
b/src/backend/distributed/metadata/node_metadata.c
index e3a1b2c..f4d5e6f 100644
--- a/src/backend/distributed/metadata/node_metadata.c
+++ b/src/backend/distributed/metadata/node_metadata.c
@@ -2965,8 +2965,18 @@
     */
- Relation replicaIndex =
index_open(RelationGetPrimaryKeyIndex(pgDistNode),
-                                      AccessShareLock);
+    #if PG_VERSION_NUM >= PG_VERSION_18
+        /* PG 18+ adds a bool "deferrable_ok" parameter */
+        Relation replicaIndex =
+            index_open(
+                RelationGetPrimaryKeyIndex(pgDistNode, false),
+                AccessShareLock);
+    #else
+        Relation replicaIndex =
+            index_open(
+                RelationGetPrimaryKeyIndex(pgDistNode),
+                AccessShareLock);
+    #endif

     ScanKeyInit(&scanKey[0], Anum_pg_dist_node_nodename,
BTEqualStrategyNumber, F_TEXTEQ, CStringGetTextDatum(nodeName));

```
  
  ```diff
  diff --git a/src/backend/distributed/operations/node_protocol.c b/src/backend/distributed/operations/node_protocol.c
index e3a1b2c..f4d5e6f 100644
--- a/src/backend/distributed/operations/node_protocol.c
+++ b/src/backend/distributed/operations/node_protocol.c
@@ -746,7 +746,12 @@
     if (!OidIsValid(idxoid))
     {
-        idxoid = RelationGetPrimaryKeyIndex(rel);
+        /* Determine the index OID of the primary key (PG18 adds a second parameter) */
+#if PG_VERSION_NUM >= PG_VERSION_18
+        idxoid = RelationGetPrimaryKeyIndex(rel, false);
+#else
+        idxoid = RelationGetPrimaryKeyIndex(rel);
+#endif
     }

     return idxoid;

```
  
Because Citus has always taken the lock immediately—just as the old
two-arg call did—we pass `false` to keep that same immediate-lock
behavior. Passing `true` would switch to deferred locking, which we
don’t want.



### Adapt `ExplainOnePlan()` to PG-18’s expanded API

PostgreSQL 18 extended
525392d572
the `ExplainOnePlan()` function to carry the `CachedPlan *` and
`CachedPlanSource *` pointers plus an explicit `query_index`, letting
the EXPLAIN machinery track plan‐source invalidation. The old signature:

```c
/* PG ≤17 */
void
ExplainOnePlan(PlannedStmt *plannedstmt,
               IntoClause *into,
               struct ExplainState *es,
               const char *queryString,
               ParamListInfo params,
               QueryEnvironment *queryEnv,
               const instr_time *planduration,
               const BufferUsage *bufusage);
```

became, in PG 18:

```c
/* PG ≥18 */
void
ExplainOnePlan(PlannedStmt *plannedstmt,
               CachedPlan   *cplan,
               CachedPlanSource *plansource,
               int            query_index,
               IntoClause    *into,
               struct ExplainState *es,
               const char   *queryString,
               ParamListInfo params,
               QueryEnvironment *queryEnv,
               const instr_time *planduration,
               const BufferUsage *bufusage,
               const MemoryContextCounters *mem_counters);
```

To compile under both versions, Citus now wraps each call in
`multi_explain.c` with:

```c
#if PG_VERSION_NUM >= PG_VERSION_18
    /* PG 18+: pass NULL for the new cached‐plan fields and zero for query_index */
    ExplainOnePlan(
        plan,         /* PlannedStmt *plannedstmt */
        NULL,         /* CachedPlan *cplan */
        NULL,         /* CachedPlanSource *plansource */
        0,            /* query_index */
        into,         /* IntoClause *into */
        es,           /* ExplainState *es */
        queryString,  /* const char *queryString */
        params,       /* ParamListInfo params */
        NULL,         /* QueryEnvironment *queryEnv */
        &planduration,/* const instr_time *planduration */
        (es->buffers ? &bufusage : NULL),
        (es->memory  ? &mem_counters : NULL)
    );
#elif PG_VERSION_NUM >= PG_VERSION_17
    /* PG 17: same as before, plus passing mem_counters if enabled */
    ExplainOnePlan(
        plan,
        into,
        es,
        queryString,
        params,
        queryEnv,
        &planduration,
        (es->buffers ? &bufusage : NULL),
        (es->memory ? &mem_counters : NULL)
    );
#else
    /* PG 15–16: original seven-arg form */
    ExplainOnePlan(
        plan,
        into,
        es,
        queryString,
        params,
        queryEnv,
        &planduration,
        (es->buffers ? &bufusage : NULL)
    );
#endif
```


### Adapt to the unified “index interpretation” API in PG 18 (commit
a8025f544854)

PostgreSQL commit
a8025f5448
generalized the old btree‐specific operator‐interpretation API into a
single “index interpretation” interface:

* **Renamed type**:
  `OpBtreeInterpretation` → `OpIndexInterpretation`
* **Renamed function**:
`get_op_btree_interpretation(opno)` →
`get_op_index_interpretation(opno)`
* **Unified field**:
  Each interpretation now carries `cmptype` instead of `strategy`.

To build cleanly on PG 18 while still supporting PG 15–17, Citus’s
shard‐pruning code now wraps these changes:

```c
#include "pg_version_constants.h"

#if PG_VERSION_NUM >= PG_VERSION_18
/* On PG 18+ the btree‐only APIs vanished; alias them to the new generic versions */
typedef OpIndexInterpretation OpBtreeInterpretation;
#define get_op_btree_interpretation(opno)  get_op_index_interpretation(opno)
#define ROWCOMPARE_NE  COMPARE_NE
#endif

/* … later, when checking an interpretation … */
OpBtreeInterpretation *interp =
    (OpBtreeInterpretation *) lfirst(cell);

#if PG_VERSION_NUM >= PG_VERSION_18
    /* use cmptype on PG 18+ */
    if (interp->cmptype == ROWCOMPARE_NE)
#else
    /* use strategy on PG 15–17 */
    if (interp->strategy == ROWCOMPARE_NE)
#endif
{
    /* … */
}
```


### Adapt `create_foreignscan_path()` for PG-18’s revised signature

PostgreSQL commit
e222534679
reordered and removed a couple of parameters in the FDW‐path builder:

* **PG 15–17 signature (11 args)**

  ```c
  create_foreignscan_path(PlannerInfo   *root,
                          RelOptInfo    *rel,
                          PathTarget    *target,
                          double         rows,
                          Cost           startup_cost,
                          Cost           total_cost,
                          List          *pathkeys,
                          Relids         required_outer,
                          Path          *fdw_outerpath,
                          List          *fdw_restrictinfo,
                          List          *fdw_private);
  ```
* **PG 18+ signature (9 args)**

  ```c
  create_foreignscan_path(PlannerInfo   *root,
                          RelOptInfo    *rel,
                          PathTarget    *target,
                          double         rows,
                          int            disabled_nodes,
                          Cost           startup_cost,
                          Cost           total_cost,
                          Relids         required_outer,
                          Path          *fdw_outerpath,
                          List          *fdw_private);
  ```

To support both, Citus now defines a compatibility macro in
`pg_version_compat.h`:

```c
#include "nodes/bitmapset.h"   /* for Relids */
#include "nodes/pg_list.h"     /* for List */
#include "optimizer/pathnode.h" /* for create_foreignscan_path() */

#if PG_VERSION_NUM >= PG_VERSION_18

/* PG18+: drop pathkeys & fdw_restrictinfo, add disabled_nodes */
#define create_foreignscan_path_compat(a, b, c, d, e, f, g, h, i, j, k) \
    create_foreignscan_path(                                            \
        (a),          /* root */                                       \
        (b),          /* rel */                                        \
        (c),          /* target */                                     \
        (d),          /* rows */                                       \
        (0),          /* disabled_nodes (unused by Citus) */           \
        (e),          /* startup_cost */                              \
        (f),          /* total_cost */                                \
        (g),          /* required_outer */                            \
        (h),          /* fdw_outerpath */                             \
        (k)           /* fdw_private */                               \
    )

#else

/* PG15–17: original signature */
#define create_foreignscan_path_compat(a, b, c, d, e, f, g, h, i, j, k) \
    create_foreignscan_path(                                            \
        (a), (b), (c), (d),                                            \
        (e), (f),                                                      \
        (g), (h), (i), (j), (k)                                        \
    )
#endif
```

Now every call to `create_foreignscan_path_compat(...)`—even in tests
like `fake_fdw.c`—automatically picks the correct argument list for
PG 15 through PG 18.



### Drop the obsolete bitmap‐scan hooks on PG 18+

PostgreSQL commit
c3953226a0
cleaned up the `TableAmRoutine` API by removing the two bitmap‐scan
callback slots:

* `scan_bitmap_next_block`
* `scan_bitmap_next_tuple`

Since those hook‐slots no longer exist in PG 18, Citus now wraps their
NULL‐initialization in a `#if PG_VERSION_NUM < PG_VERSION_18` guard. On
PG 15–17 we still explicitly set them to `NULL` (to satisfy the old
struct layout), and on PG 18+ we omit them entirely:

```c

#if PG_VERSION_NUM < PG_VERSION_18
    /* PG 15–17 only: these fields were removed upstream in PG 18 */
    .scan_bitmap_next_block = NULL,
    .scan_bitmap_next_tuple = NULL,
#endif


```


### Adapt `vac_update_relstats()` invocation to PG-18’s new
“all\_frozen” argument

PostgreSQL commit
99f8f3fbbc
extended the `vac_update_relstats()` API by inserting a
`num_all_frozen_pages` parameter between the existing
`num_all_visible_pages` and `hasindex` arguments:

```diff
- /* PG ≤17: */
- void
- vac_update_relstats(Relation relation,
-                    BlockNumber num_pages,
-                    double     num_tuples,
-                    BlockNumber num_all_visible_pages,
-                    bool       hasindex,
-                    TransactionId frozenxid,
-                    MultiXactId  minmulti,
-                    bool      *frozenxid_updated,
-                    bool      *minmulti_updated,
-                    bool       in_outer_xact);
+ /* PG ≥18: adds num_all_frozen_pages */
+ void
+ vac_update_relstats(Relation    relation,
+                    BlockNumber num_pages,
+                    double      num_tuples,
+                    BlockNumber num_all_visible_pages,
+                    BlockNumber num_all_frozen_pages,
+                    bool        hasindex,
+                    TransactionId frozenxid,
+                    MultiXactId  minmulti,
+                    bool      *frozenxid_updated,
+                    bool      *minmulti_updated,
+                    bool       in_outer_xact);
```

To compile cleanly on both PG 15–17 and PG 18+, Citus wraps its call in
a version guard and supplies a zero placeholder for the new field:

```c
#if PG_VERSION_NUM >= 180000
    /* PG 18+: supply explicit “all_frozen” count */
    vac_update_relstats(
        rel,
        new_rel_pages,
        new_live_tuples,
        new_rel_allvisible,    /* allvisible */
        0,                     /* all_frozen */
        nindexes > 0,
        newRelFrozenXid,
        newRelminMxid,
        &frozenxid_updated,
        &minmulti_updated,
        false                  /* in_outer_xact */
    );
#else
    /* PG 15–17: original signature */
    vac_update_relstats(
        rel,
        new_rel_pages,
        new_live_tuples,
        new_rel_allvisible,
        nindexes > 0,
        newRelFrozenXid,
        newRelminMxid,
        &frozenxid_updated,
        &minmulti_updated,
        false                  /* in_outer_xact */
    );
#endif
```

**Why all_frozen = 0?**
Columnar storage never embeds transaction IDs in its pages, so it never
needs to track “all‐frozen” pages the way a heap does. Setting both
allvisible and allfrozen to zero simply tells Postgres “there are no
pages with the visibility or frozen‐status bits set,” matching our
existing behavior.

This change ensures Citus’s VACUUM‐statistic updates work unmodified
across all supported Postgres versions.
2025-07-16 15:30:41 +03:00
Naisila Puka c98341e4ed
Bump PG versions to 17.5, 16.9, 15.13 (#7986)
Nontrivial bump because of the following PG15.3 commit
317aba70e
https://github.com/postgres/postgres/commit/317aba70e

Previously, when views were converted to RTE_SUBQUERY the relid
would be cleared in PG15. In this patch of PG15, relid is retained.
Therefore, we add a check with the "relkind and rtekind" to
identify the converted views in 15.13

Sister PR https://github.com/citusdata/the-process/pull/164
Using dev image sha because I encountered the libpq
symlink issue again with "-v219b87c"
2025-05-22 14:08:03 +02:00
Naisila Puka a18040869a
Error out for queries with outer joins and pseudoconstant quals in PG<17 (#7937)
PG15 commit d1ef5631e620f9a5b6480a32bb70124c857af4f1
and PG16 commit 695f5deb7902865901eb2d50a70523af655c3a00
disallow replacing joins with scans in queries with pseudoconstant quals.
This commit prevents the set_join_pathlist_hook from being called
if any of the join restrictions is a pseudo-constant.
So in these cases, citus has no info on the join, never sees that
the query has an outer join, and ends up producing an incorrect plan.
PG17 fixes this by commit 9e9931d2bf40e2fea447d779c2e133c2c1256ef3
Therefore, we take this extra measure here for PG versions less than 17.
hasOuterJoin can never be true when set_join_pathlist_hook is absent.
2025-05-11 21:47:28 +00:00
Mehmet YILMAZ a4040ba5da
Planner: lift volatile target‑list items in `WrapSubquery` to coordinator (prevents sequence‑leap in distributed `INSERT … SELECT`) (#7976)
This PR fixes #7784 and refactors the `WrapSubquery(Query *subquery)`
function to improve clarity and correctness when handling volatile
expressions in subqueries during Citus insert-select rewriting.

### Background

The `WrapSubquery` function rewrites a query of the form:

```sql
INSERT INTO target_table SELECT ... FROM ...
```

...by wrapping the `SELECT` in a subquery:

```sql
SELECT <outer-TL>
  FROM ( <subquery with volatile expressions replaced with NULL> ) citus_insert_select_subquery
```

This transformation allows:

* **Volatile expressions** (e.g., `nextval`, `now`) **not used in `GROUP
BY` or `ORDER BY`** to be evaluated **exactly once on the coordinator**.
* **Stable/immutable or sort-relevant expressions** to remain in the
worker-executed subquery.
* Placeholder `NULL`s to maintain column alignment in the inner
subquery.

### Fix Details

* Restructured the code into labeled logical sections:

  1. Build wrapper query (`SELECT … FROM (subquery)`)
  2. Rewrite target lists with volatility analysis
  3. Assign and return updated query trees
  
* Preserved existing behavior, focusing on clarity and maintainability.

### How the new code handles volatile items

stage | what we look for | what we do | why
-- | -- | -- | --
scan target list once | 1. `expr_is_volatile(te->expr)` 2.
`te->ressortgroupref != 0` (is the column used in GROUP BY / ORDER BY?)
| decide whether to hoist or keep | we must not hoist an expression the
inner query still needs for sorting/grouping, otherwise its
`SortGroupClause` breaks
volatile & not used in sort/group | deep‑copy the expression into the
outer target list | executes once on the coordinator |  
  | leave a typed `NULL `placeholder (visible, not `resjunk`) in the
inner target list | keeps column numbering stable for helpers that
already ran (reorder, cast); the worker sends a cheap constant |  
stable / immutable, or volatile but used in sort/group | keep the
original expression in the inner list; outer list references it via a
`Var `| workers can evaluate it safely and, if needed, the inner
ORDER BY still works |  

###  Example

Given this query:

```sql
INSERT INTO t SELECT nextval('s'), 42 FROM generate_series(1, 2);
```

The planner rewrites it as:

```sql
SELECT nextval('s'), col2
  FROM (SELECT NULL::bigint AS col1, 42 AS col2 FROM generate_series(1, 2)) citus_insert_select_subquery;
```

This ensures `nextval('s')` is evaluated only once per row on the
**coordinator**, not on each worker node, preserving correct sequence
semantics.

#### **Outer‑Var guard (`FindReferencedTableColumn`)**

Because `WrapSubquery` adds an extra query level, lots of Vars that the
old code never expected become “outer” Vars; without teaching
`FindReferencedTableColumn` to climb that extra level reliably, Citus
would intermittently reject valid foreign keys and even hit asserts.

* Re‑implemented the outer‑Var guard so that the function:

* **Walks deterministically up the query stack** when `skipOuterVars =
false` (default for FK / UNION checks). A new while‑loop copies — rather
than truncates — `parentQueryList` on each hop, eliminating
list‑aliasing that made *issue 5248* fail intermittently in parallel
regressions.

* Handles multi‑level `varlevelsup` in a single loop; never mutates the
caller’s list in place.
2025-05-06 17:45:49 +03:00
Onur Tirtir ea7aa6712d
Move stat view implementations into a submodule (#7975)
Also move serialize_distributed_ddls into commands submodule, seems like
an oversight from last year (by me).
2025-04-29 14:22:29 +03:00
manaldush 0e6127c4f6
AddressSanitizer: stack-use-after-scope on distributed_planner:HasUnresolvedExternParamsWalker (#7948)
Var externParamPlaceholder is created on stack, and its address is used
for paramFetch. Postgres code return address of externParamPlaceholder
var to externParam, then code flow go out of scope and dereference
pointer on stack out of scope.

Fixes https://github.com/citusdata/citus/issues/7941.

---------

Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>
2025-04-04 13:27:56 +00:00
Cédric Villemain a7e686c106
Make sure to prevent INSERT INTO ... SELECT queries involving subfield or sublink (#7912)
DESCRIPTION: Makes sure to prevent `INSERT INTO ... SELECT` queries involving subfield or sublink, to avoid crashes

The following query was crashing the backend:

```
INSERT INTO field_indirection_test_1 (
  int_col, ct1_col.int_1,ct1_col.int_2
) SELECT 0, 1, 2;
-- crash
```

En passant, added more tests with sublink in distributed_types and found
another query with wrong behavior:

```
INSERT INTO domain_indirection_test (f1,f3.if1) SELECT 0, 1;
ERROR:  could not find a conversion path from type 23 to 17619
-- not the expected ERROR
```

Fixed them by using `strip_implicit_coercions()` on target entry
expression before checking for the presence of a subscript or
fieldstore, else we fail to find the existing ones and wrongly accept to
execute unsafe query.
2025-03-27 09:39:43 +00:00
Mehmet YILMAZ e50563fbd8 Issue 7887 Enhance AddInsertSelectCasts for Identity Columns (#7920)
## Enhance `AddInsertSelectCasts` for Identity Columns


This PR fixes #7887 and improves the behavior of partial inserts into
**identity columns** by modifying the **`AddInsertSelectCasts`**
function. Specifically, we introduce **special-case handling** for
`nextval(...)` calls (represented in the parse tree as `NextValueExpr`)
to ensure that if the identity column’s declared type differs from
`nextval`’s default return type (`int8`), we **cast** the expression
properly. This prevents mismatches like `int8` → `int4` from causing
“invalid string enlargement” errors or other type-related failures.

When `INSERT ... SELECT` is processed, `AddInsertSelectCasts` reconciles
each target column’s type with the corresponding SELECT expression’s
type. Historically, for identity columns that rely on `nextval(...)`, we
can end up with a mismatch:
- `nextval` returns **`int8`**,
- The identity column might be **`int4`**, **`bigint`**, or another
integer type.

Without a correct cast, Postgres or Citus can produce plan-time or
runtime errors. By **detecting** `NextValueExpr` and applying a cast to
the column’s type, the final plan ensures consistent insertion without
errors.

## What Changed

1. **Check for `NextValueExpr`**:  
   In `AddInsertSelectCasts`, we now have a code block:
   ```c
   if (IsA(selectEntry->expr, NextValueExpr))
   {
       Oid nextvalType = GetNextvalReturnTypeCatalog();
       ...
// If (targetType != nextvalType), build a cast from int8 -> targetType
   }
   else
   {
       // fallback to generic mismatch logic
   }
   ```
This short-circuits any expression that’s a `nextval(...)` call, letting
us explicitly cast to the correct type.

2. **Fallback Generic Logic**:  
If it isn’t a `NextValueExpr` (i.e. a normal column or expression
mismatch), we still rely on the existing path that compares `sourceType`
vs. `targetType` and calls `CastExpr(...)` if they differ.

3. **`GetNextvalReturnTypeCatalog`**:  
We added or refined a helper function to confirm that `nextval` returns
`int8`, or do a `LookupFuncName("nextval", ...)` to discover the
function’s return type from `pg_proc`—making it robust if future changes
happen.

## Benefits

- **Partial inserts** into identity columns no longer fail with type
mismatches.
- When `nextval` yields `int8` but the identity column is `int4` (or
another type), we properly cast to the column’s type in the plan.
- Preserves the **existing** approach for other columns—only identity
calls get the specialized `NextValueExpr` logic.

## Testing

- Extended `generatedidentity.sql` test scenario to cover partial
inserts into both `GENERATED ALWAYS` and `GENERATED BY DEFAULT` identity
columns, including tests for the `OVERRIDING SYSTEM VALUE` clause and
partial inserts referencing foreign-key columns.
2025-03-12 12:43:01 +03:00
Colm 4139370a1d #7782 - catch when Postgres planning removes all Citus tables (#7907)
DESCRIPTION: fix a planning error caused by a redundant WHERE clause

Fix a Citus planning glitch that occurs in a DML query when the WHERE
clause of the query is of the form:
    ` WHERE true OR <expression with 1 or more citus tables> `
and this is the only place in the query referencing a citus table.
Postgres' standard planner transforms the WHERE clause to:
    ` WHERE true `
So the query now has no citus tables, confusing the Citus planner as
described in issues #7782 and #7783. The fix is to check, after Postgres
standard planner, if the Query has been transformed as shown, and re-run
the check of whether or not the query needs distributed planning.
2025-03-12 12:43:01 +03:00
Mehmet YILMAZ 87ec3def55 Fix 0-Task Plans in Single-Shard Router When Updating a Local Table with Reference Table in Subquery (#7897)
This PR fixes an issue #7891 in the Citus planner where an `UPDATE` on a
local table with a subquery referencing a reference table could produce
a 0-task plan. Historically, the planner sometimes failed to detect that
both the target and referenced tables were effectively “local,”
assigning `INVALID_SHARD_ID `and yielding a no-op plan.

### Root Cause

- In the Citus router logic (`PlanRouterQuery`), we relied on `shardId`
to determine whether a query should be routed to a single shard.
- If `shardId == INVALID_SHARD_ID`, but we also had not marked the query
as a “local table modification,” the code path would produce zero tasks.
- Local + reference tables do not require multi-shard routing. Failing
to detect this “purely local” scenario caused Citus to incorrectly route
to zero tasks.

### Changes

**Enhanced Local Table Detection**

- Updated `IsLocalTableModification` and related checks to consider both
local and reference tables as “local” for planning, preventing the
0-task scenario.
- Expanded `ContainsOnlyLocalOrReferenceTables` to return true if there
are no fully distributed tables in the query.

**Added Regress Test**

- Introduced a new regress test (`issue_7891.sql`) which reproduces the
scenario.
- Verifies we get a valid single- or local-task plan rather than a
0-task plan.
2025-03-12 12:43:01 +03:00
Colm ec141f696a Enhance MERGE .. WHEN NOT MATCHED BY SOURCE for repartitioned source (#7900)
DESCRIPTION: Ensure that a MERGE command on a distributed table with a
`WHEN NOT MATCHED BY SOURCE` clause runs against all shards of the
distributed table.

The Postgres MERGE command updates a table using a table or a query as a
data source. It provides three ways to match the target table with the
source: `WHEN MATCHED` means that there is a row in both the target and
source; `WHEN NOT MATCHED` means that there is a row in the source that
has no match (is not present) in the target; and, as of PG17, `WHEN NOT
MATCHED BY SOURCE` means that there is a row in the target that has no
match in the source.

In Citus, when a MERGE command updates a distributed table using a
local/reference table or a distributed query as source, that source is
repartitioned, and for each repartitioned shard that has data (i.e. 1 or
more rows) the MERGE is run against the corresponding distributed table
shard. Suppose the distributed table has 32 shards, and the source
repartitions into 4 shards that have data, with the remaining 28 shards
being empty; then the MERGE command is performed on the 4 corresponding
shards of the distributed table. However, the semantics of `WHEN NOT
MATCHED BY SOURCE` are that the specified action must be performed on
the target for each row in the target that is not in the source; so if
the source is empty, all target rows should be updated. To see this,
consider the following MERGE command:
```
MERGE INTO target AS t
USING source AS s ON t.id = s.id
WHEN NOT MATCHED BY SOURCE THEN UPDATE t SET t.col1 = 100
```
If the source has zero rows then every row in the target is updated s.t.
its col1 value is 100. Currently in Citus a MERGE on a distributed table
with a local/reference table or a distributed query as source ignores
shards of the distributed table when the corresponding shard of the
repartitioned source has zero rows. However, if the MERGE command
specifies a `WHEN NOT MATCHED BY SOURCE` clause, then the MERGE should
be performed on all shards of the distributed table, to ensure that the
specified action is performed on the target for each row in the target
that is not in the source. This PR enhances Citus MERGE execution so
that when a repartitioned source shard has zero rows, and the MERGE
command specifies a `WHEN NOT MATCHED BY SOURCE` clause, the MERGE is
performed against the corresponding shard of the distributed table using
an empty (zero row) relation as source, by generating a query of the
form:
```
MERGE INTO target_shard_0002 AS t
USING (SELECT id FROM (VALUES (NULL) ) source_0002(id) WHERE FALSE) AS s ON t.id = s.id
WHEN NOT MATCHED BY SOURCE THEN UPDATE t set t.col1 = 100
```
This works because each row in the target shard will be updated, and
`WHEN MATCHED` and `WHEN NOT MATCHED`, if specified, will be no-ops
because the source has zero rows.

To implement this when the source is a local or reference table involves
teaching function `ExcuteSourceAtCoordAndRedistribution()` in
`merge_executor.c` to not prune tasks when the query has `WHEN NOT
MATCHED BY SOURCE` but to instead replace the task's query to one that
uses an empty relation as source. And when the source is a distributed
query, function
`ExecuteMergeSourcePlanIntoColocatedIntermediateResults()` (also in
`merge_executor.c`) instead of skipping empty tasks now generates a
query that uses an empty relation as source for the corresponding target
shard of the distributed table, but again only when the query has `WHEN
NOT MATCHED BY SOURCE`. A new function `BuildEmptyResultQuery()` is
added to `recursive_planning.c` and it is used by both the
aforementioned functions in `merge_executor.c` to build an empty
relation to use as the source. It applies the appropriate type to each
column of the empty relation so the join with the target makes sense to
the query compiler.
2025-03-12 12:43:01 +03:00
Colm 89674d9630 [Bug Fix] SEGV on query with Left Outer Join (#7787) (#7901)
DESCRIPTION: Fixes a crash in left outer joins that can happen when
there is an an aggregate on a column from the inner side of the join.

Fix the SEGV seen in #7787 and #7899; it occurs because a column in the
targetlist of a worker subquery can contain a non-empty varnullingrels
field if the column is from the inner side of a left outer join. The
issue can also occur with the columns in the HAVING clause, and this is
also tested in the fix. The issue was triggered by the introduction of
the varnullingrels to Vars in Postgres 16 (2489d76c)

There is a related issue, #7705, where a non-empty varnullingrels was
incorrectly copied into the query tree for the combine query. Here, a
non-empty varnullingrels field of a var is incorrectly copied into the
query tree for a worker subquery.

The regress file from #7705 is used (and renamed) to also test this
(#7787). An alternative test output file is required for Postgres 15
because of an optimization to DISTINCT in Postgres 16 (1349d2790bf).
2025-03-12 12:43:01 +03:00
Naisila Puka 3b1c082791 Drops PG14 support (#7753)
DESCRIPTION: Drops PG14 support

1. Remove "$version_num" != 'xx' from configure file
2. delete all PG_VERSION_NUM = PG_VERSION_XX references in the code
3. Look at pg_version_compat.h file, remove all _compat functions etc
defined specifically for PGXX differences
4. delete all PG_VERSION_NUM >= PG_VERSION_(XX+1), PG_VERSION_NUM <
PG_VERSION_(XX+1) ifs in the codebase
5. delete ruleutils_xx.c file
6. cleanup normalize.sed file from pg14 specific lines
7. delete all alternative output files for that particular PG version,
server_version_ge variable helps here
2025-03-12 12:43:01 +03:00
Naisila Puka 0642a4dc08 Propagate MERGE ... WHEN NOT MATCHED BY SOURCE (#7807)
DESCRIPTION: Propagates MERGE ... WHEN NOT MATCHED BY SOURCE

It seems like there is not much needed to be done here.
`get_merge_query_def` from `ruleutils_17` is updated with "WHEN NOT
MATCHED BY SOURCE" therefore `deparse_shard_query` parses the merge
query for execution on the shard correctly.

Relevant PG commit:
https://github.com/postgres/postgres/commit/0294df2f1
2025-03-12 12:43:00 +03:00
Naisila Puka 74d945f5ae PG17 - Propagate EXPLAIN options: MEMORY and SERIALIZE (#7802)
DESCRIPTION: Propagates MEMORY and SERIALIZE options of EXPLAIN

The options for `MEMORY` can be true or false. Default is false.
The options for `SERIALIZE` can be none, text or binary. Default is
none.

I referred to how we added support for WAL option in this PR [Support
EXPLAIN(ANALYZE, WAL)](https://github.com/citusdata/citus/pull/4196).
For the tests however, I used the same tests as Postgres, not like the
tests in the WAL PR. I used exactly the same tests as Postgres does, I
simply distributed the table beforehand. See below the relevant Postgres
commits from where you can see the tests added as well:
- [Add EXPLAIN
(MEMORY)](https://github.com/postgres/postgres/commit/5de890e36)
- [Invent SERIALIZE option for
EXPLAIN.](https://github.com/postgres/postgres/commit/06286709e)

This PR required a lot of copying of Postgres static functions regarding
how `EXPLAIN` works for `MEMORY` and `SERIALIZE` options. Specifically,
these copy-pastes were required for updating `ExplainWorkerPlan()`
function, which is in fact based on postgres' `ExplainOnePlan()`:
```C
/* copied from explain.c to update ExplainWorkerPlan() in citus according to ExplainOnePlan() in postgres */
#define BYTES_TO_KILOBYTES(b)
typedef struct SerializeMetrics
static bool peek_buffer_usage(ExplainState *es, const BufferUsage *usage);
static void show_buffer_usage(ExplainState *es, const BufferUsage *usage);
static void show_memory_counters(ExplainState *es, const MemoryContextCounters *mem_counters);
static void ExplainIndentText(ExplainState *es);
static void ExplainPrintSerialize(ExplainState *es, SerializeMetrics *metrics);
static SerializeMetrics GetSerializationMetrics(DestReceiver *dest);
```

_Note_: it looks like we were missing some `buffers` option details as
well. I put them together with the memory option, like the code in
Postgres explain.c, as I didn't want to change the copied code. However,
I tested locally and there is no big deal in previous Citus versions,
and you can also see that existing Citus tests with `buffers true`
didn't change. Therefore, I prefer not to backport "buffers" changes to
previous versions.
2025-03-12 12:43:00 +03:00
Naisila Puka 3e96a19606 Adds JSON_TABLE() support, and SQL/JSON constructor/query functions tests (#7816)
DESCRIPTION: Adds JSON_TABLE() support

PG17 has added basic `JSON_TABLE()` functionality
`JSON_TABLE()` allows `JSON` data to be converted into a relational view
and thus used, for example, in a `FROM` clause, like other tabular data.

We treat `JSON_TABLE` the same as correlated functions (e.g., recurring
tuples). In the end, for multi-shard `JSON_TABLE` commands, we apply the
same restrictions as reference tables (e.g., cannot perform a lateral
outer join when a distributed subquery references a (reference
table)/(json table) etc.)

Relevant PG17 commits:
[basic JSON
table](https://github.com/postgres/postgres/commit/de3600452), [nested
paths in json
table](https://github.com/postgres/postgres/commit/bb766cde6)

Onder had previously added json table support for PG15BETA1, but we
reverted that commit because json table was reverted in PG15.
ce7f1a530f
Previous relevant PG15Beta1 commit:
https://github.com/postgres/postgres/commit/4e34747c8
Therefore, I referred to Onder's commit for this commit as well, with a
few changes due to some differences between PG15/PG17:

1) In PG15Beta1, we had also `PLAN` clauses for `JSON_TABLE`
https://github.com/postgres/postgres/commit/fadb48b00, and Onder's
commit includes tests for those as well. However, `PLAN` nodes are _not_
added in PG17. Therefore, I didn't include the `json_table_select_only`
test, which had mostly queries involving `PLAN`. I only included the
last query from that test.

2) In PG15 timeline (Citus 11.1), we didn't support outer joins where
the outer rel is a recurring one and the inner one is a non-recurring
one. However, [Onur added support for that one in Citus
11.2](https://github.com/citusdata/citus/pull/6512), therefore I updated
the tests from Onder's commit accordingly.

3) PG17 json table has nested paths and columns, therefore I added a
test
with a distributed table, which is exactly the same as the one in
sqljson_jsontable in PG17.
https://github.com/postgres/postgres/commit/bb766cde6

This pull request also adds some basic tests on validation of SQL/JSON
constructor functions JSON(), JSON_SCALAR(), and JSON_SERIALIZE(),
and also SQL/JSON query functions JSON_EXISTS(), JSON_QUERY(), and
JSON_VALUE(). The relevant PG commits are the following:
[JSON(), JSON_SCALAR(),
JSON_SERIALIZE()](https://github.com/postgres/postgres/commit/03734a7fe)
[JSON_EXISTS(), JSON_VALUE(),
JSON_QUERY()](https://github.com/postgres/postgres/commit/6185c9737)
2025-03-12 12:26:05 +03:00
Teja Mupparti 35d1160ace PG17 Compatibility: Support MERGE features in Citus with clean exceptions (#7781)
- Adapted `pgmerge.sql` tests from PostgreSQL community's `merge.sql` to
Citus by converting tables into Citus local tables.
- Identified two new PostgreSQL 17 MERGE features (`RETURNING` support
and MERGE on updatable views) not yet supported by Citus.
- Implemented changes to detect unsupported features and raise clean
exceptions, ensuring pgmerge tests pass without diffs.
- Addressed breaking changes caused by `MERGE ... WHEN NOT MATCHED BY
SOURCE` restructuring, reducing diffs in pgmerge tests.
- Segregated unsupported test cases into `merge_unsupported.sql` to
maintain clarity and avoid large diffs in test files.
- Prepared the Citus MERGE planner to handle new PostgreSQL changes,
reducing remaining test discrepancies.

All merge tests now pass cleanly, with unsupported cases clearly
isolated.

Relevant PG commits:
c649fa24a
https://github.com/postgres/postgres/commit/c649fa24a
0294df2f1
https://github.com/postgres/postgres/commit/0294df2f1
---------

Co-authored-by: naisila <nicypp@gmail.com>
2025-03-12 12:25:49 +03:00
Naisila Puka dce54db494 PG17 compatibility: Resolve compilation issues (#7699)
This PR provides successful compilation against PG17.0.

- Remove ExecFreeExprContext call
Relevant PG commit
d060e921ea5aa47b6265174c32e1128cebdbc3df
d060e921ea

- PG17 uses streaming IO in analyze, fix scan_analyze_next_block function
Relevant PG commit
041b96802efa33d2bc9456f2ad946976b92b5ae1
041b96802e

- Define ObjectClass for PG17+ only since it's removed
Relevant PG commit:
89e5ef7e21812916c9cf9fcf56e45f0f74034656
89e5ef7e21

- Remove ReorderBufferTupleBuf structure.
Relevant PG commit:
08e6344fd6423210b339e92c069bb979ba4e7cd6
08e6344fd6

- Define colliculocale and daticulocale since they have been renamed
Relevant PG commit:
f696c0cd5f299f1b51e214efc55a22a782cc175d
f696c0cd5f

- makeStringConst defined in PG17
Relevant PG commit:
de3600452b61d1bc3967e9e37e86db8956c8f577
de3600452b

- RangeVarCallbackOwnsTable was replaced by RangeVarCallbackMaintainsTable
Relevant PG commit:
ecb0fd33720fab91df1207e85704f382f55e1eb7
ecb0fd3372

- attstattarget is nullable, define pg compatible functions for it
Relevant PG commit:
4f622503d6de975ac87448aea5cea7de4bc140d5
4f622503d6

- stxstattarget is nullable in PG17, write compat functions for it
Relevant PG commit:
012460ee93c304fbc7220e5b55d9d0577fc766ab
012460ee93

- Use ResourceOwner to track WaitEventSet in PG17
Relevant PG commit:
50c67c2019ab9ade8aa8768bfe604cd802fe8591
50c67c2019

- getIdentitySequence now uses Relation instead of relation_id
Relevant PG commit:
509199587df73f06eda898ae13284292f4ae573a
509199587d

- Remove no-op tuplestore_donestoring function
Relevant PG commit:
75680c3d805e2323cd437ac567f0677fdfc7b680
75680c3d80

- MergeAction can have 3 merge kinds (now enum) in PG17, write compat
Relevant PG commit:
0294df2f1f842dfb0eed79007b21016f486a3c6c
0294df2f1f

- EXPLAIN (MEMORY) is added, make changes to ExplainOnePlan
Relevant PG commit:
5de890e3610d5a12cdaea36413d967cf5c544e20
5de890e361

- LIMIT_OPTION_DEFAULT has been removed as it's useless, use LIMIT_OPTION_COUNT
Relevant PG commit:
a6be0600ac3b71dda8277ab0fcbe59ee101ac1ce
a6be0600ac

- write compat for create_foreignscan_path bcs of more arguments in PG17
Relevant PG commit:
9e9931d2bf40e2fea447d779c2e133c2c1256ef3
9e9931d2bf

- pgprocno and lxid have been combined into a struct in PGPROC
Relevant PG commits:
28f3915b73f75bd1b50ba070f56b34241fe53fd1
28f3915b73

ab355e3a88de745607f6dd4c21f0119b5c68f2ad
ab355e3a88

024c521117579a6d356050ad3d78fdc95e44eefa
024c521117

- Simplify CitusNewNode (#7434)
postgres refactored newNode() in PG 17, the main point for doing this is
the original tricks is no longer neccessary for modern compilers[1].
This does the same for Citus.
This should have no backward compatibility issues since it just replaces
palloc0fast with palloc0.
This is good for forward compatibility since palloc0fast no longer
exists in PG 17.
[1]
https://www.postgresql.org/message-id/b51f1fa7-7e6a-4ecc-936d-90a8a1659e7c@iki.fi
(cherry picked from commit 4b295cc)
2025-03-12 11:01:49 +03:00
Naisila Puka 6bd3474804 Rename foreach_ macros to foreach_declared_ macros (#7700)
This is prep work for successful compilation with PG17

PG17added foreach_ptr, foreach_int and foreach_oid macros
Relevant PG commit
14dd0f27d7cd56ffae9ecdbe324965073d01a9ff

14dd0f27d7

We already have these macros, but they are different with the
PG17 ones because our macros take a DECLARED variable, whereas
the PG16 macros declare a locally-scoped loop variable themselves.

Hence I am renaming our macros to foreach_declared_

I am separating this into its own PR since it touches many files. The
main compilation PR is https://github.com/citusdata/citus/pull/7699
2025-03-12 11:01:49 +03:00