WORKER_LENGTH + 1 is too large. Fixing this has no impact on the string
that is ultimately copied, as it's impossible for the source string to
be any larger to begin with.
multi_ExecutorStart() replaces the original planned statement with the
master select statement. As that hasn't gone through the parse analysis
hooks, it'll not have a associated queryId. This prevents extensions
pg_stat_statements to show useful data associated with the query.
I came across several places we weren't as flexible or resilient as we
should have been in our build logic. They include:
* Not using `DESTDIR` in the install-header destination
* Allowing callers to specify `VPATH` or `srcdir` (which breaks)
* Using absolute path for SCRIPTS (9.5 prepends srcdir)
* Including libpq-int in a confusing way (extracted this function)
* Having server includes come first during csql build (client must)
In particular, I hit all of these attempting to build with pg_buildext
in Debian. It passes in an explicit VPATH, as well as srcdir (breaking
all recursive make invocations), and also uses DESTDIR during install.
In addition, a PGDG-enabled Debian box will have the latest libpq-dev
headers (e.g. 9.5) even when building against an older server version
(e.g. 9.4). This leads to problems when including e.g. `c.h`, which
is ambiguous. While compiling more client-side code (csql), we need to
ensure the newer libpq headers are included _first_, so I fixed that.
Though Citus' Task struct has a shardId field, it doesn't have the same
semantics as the one previously used in pg_shard code. The analogous
field in the Citus Task is anchorShardId. I've also added an argument
check to the relevant locking function to catch future locking attempts
which pass an invalid argument.
- Flexed the check which prevented append operation cstore tables
since its storage type is not SHARD_STORAGE_TABLE.
- Used process utility function to perform copy operation in
worker_append_table_to shard() instead of directly calling
postgresql DoCopy().
- Removed the additional check in master_create_empty_shard() function.
This check was redundant and erroneous since it was called after
CheckDistributedTable() call.
- Modified WorkerTableSize() function to retrieve cstore table shard
size correctly.
After this change, shards and associated metadata are automatically
dropped when running DROP TABLE on a distributed table, which fixes#230.
It also adds schema support for master_apply_delete_command, which
fixes#73.
Dropping the shards happens in the master_drop_all_shards UDF, which is
called from the SQL_DROP trigger. Inside the trigger, the table is no
longer visible and calling master_apply_delete_command directly wouldn't
work and oid <-> name mappings are not available. The
master_drop_all_shards function therefore takes the relation id, schema
name, and table name as parameters, which can be obtained from
pg_event_trigger_dropped_objects() in the SQL_DROP trigger. If the user
calls master_drop_all_shards while the table still exists, the schema
name and table name are ignored.
Author: Marco Slot
Reviewed-By: Andres Freund
I removed two braces to have this function remain more similar to the
original PostgreSQL function and added uncrustify commands to disable
formatting of its contents.
All citusdb references in
- extension, binary names
- file headers
- all configuration name prefixes
- error/warning messages
- some functions names
- regression tests
are changed to be citus.
The postgres_fdw extension has an extern function with an identical
signature, which can cause problems when both extensions are loaded.
A simple rename can fix this for now (this is the only function with)
such a conflict.
Previously we used, for historical reasons, MessageContext.
That is problematic if a single message from the client
causes a lot of statements to be planned. E.g. for the
copy_to_distributed_table script one insert statement
is planned for each row inserted via COPY, and only freed
when COPY has finished.
This entirely removes any restriction on the type of partitioning
during DML planning and execution. Though there aren't actually any
technical limitations preventing DML commands against append- (or even
range-) partitioned tables, we had initially forbidden this, as any
future stage operation could cause shards to overlap, banning all
subsequent DML operations to partition values contained within more
than one shards. This ended up mostly restricting us, so we're now
removing that restriction.
When two data types have the same binary representation, PostgreSQL may
add an implicit coercion between them by wrapping a node in a relabel
type. This wrapper signals that the wrapped value is completely binary
compatible with the designated "final type" of the relabel node. As an
example, the varchar type is often relabeled to text, since functions
provided for use with text (comparisons, hashes, etc.) are completely
compatible with varchar as well.
The hash-partitioned codepath contains functions that verify queries
actually contain an equality constraint on the partition column, but
those functions expect such constraints to be comparison operations
between a Var and Const. The RelabelType wrapper node causes these
functions to always return false, which bypasses shard pruning.
Jason Petersen
Andres Freund
Marco Slot
Murat Tuncer
Metin Doslu
Murat Tuncer
Jason Petersen
Önder Kalacı