## 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.
This commit is the second and last phase of dropping PG13 support.
It consists of the following:
- Removes all PG_VERSION_13 & PG_VERSION_14 from codepaths
- Removes pg_version_compat entries and columnar_version_compat entries
specific for PG13
- Removes alternative pg13 test outputs
- Removes PG13 normalize lines and fix the test outputs based on that
It is a continuation of 5bf163a27d
Allow using generated identity column based on int/smallint when
creating a distributed table so that applications that rely on
those data types don't break.
Inserting into / modifying such columns from workers is not allowed
but it's better than not allowing such columns altogether.
This pull request proposes a change to the logic used for propagating
identity columns to worker nodes in citus. Instead of creating a
dependent sequence for each identity column and changing its default
value to `nextval(seq)/worker_nextval(seq)`, this update will pass the
identity columns as-is to the worker nodes.
Please note that there are a few limitations to this change.
1. Only bigint identity columns will be allowed in distributed tables to
ensure compatibility with the DDL from any node functionality. Our
current distributed sequence implementation only allows insert
statements from all nodes for bigint sequences.
2. `alter_distributed_table` and `undistribute_table` operations will
not be allowed for tables with identity columns. This is because we do
not have a proper way of keeping sequence states consistent across the
cluster.
DESCRIPTION: Prevents using identity columns on data types other than
`bigint` on distributed tables
DESCRIPTION: Prevents using `alter_distributed_table` and
`undistribute_table` UDFs when a table has identity columns
DESCRIPTION: Fixes a bug that prevents enforcing identity column
restrictions on worker nodes
Depends on #6740Fixes#6694
Mehmet YILMAZ
Naisila Puka
Onur Tirtir
Gokhan Gulbiz