Updated the CI and Docker files for the PG18 branch to point to
PG18 and PostgreSQL version 18.

Updated the labeler and branch security files for PG18.

Some of these only apply to the master branch but are updated
for consistency.

modified:   .asf.yaml
modified:   .github/labeler.yml
modified:   .github/workflows/go-driver.yml
modified:   .github/workflows/installcheck.yaml
modified:   .github/workflows/jdbc-driver.yaml
modified:   .github/workflows/nodejs-driver.yaml
modified:   .github/workflows/python-driver.yaml
modified:   docker/Dockerfile
modified:   docker/Dockerfile.dev
modified:   drivers/docker-compose.yml

* [PG18 port][Set1] Fix header dependencies and use TupleDescAttr macro

- Include executor/executor.h for PG18 header reorganization and use 
  TupleDescAttr() accessor macro instead of direct attrs[] access.

* [PG18 port][Set2] Adapt to expandRTE signature change and pg_noreturn

- Add VarReturningType parameter to expandRTE() calls using VAR_RETURNING_DEFAULT.
- Replace pg_attribute_noreturn() with pg_noreturn prefix specifier.

* [PG18 port][Set3] Fix double ExecOpenIndices call for PG18 compatibility

- PG18 enforces stricter assertions in ExecOpenIndices, requiring
  ri_IndexRelationDescs to be NULL when called.

- In update_entity_tuple(), indices may already be opened by the
  caller (create_entity_result_rel_info), causing assertion failures.

- Add a check to only open indices if not already open, and track
  ownership with a boolean flag to ensure we only close what we opened.

- Found when regression tests failed with assertions, which this change
  resolves.

* [PG18 port][Set4] Update regression test expected output for ordering

PG18's implementation changes result in different row ordering for
queries without explicit ORDER BY clauses. Update expected output
files to reflect the new ordering while maintaining identical
result content.

* [PG18 port][Set5] Address review comments - coding standard fix

Note: Assisted by GitHub Copilot Agent mode.

Updated the CI BaseDockerizedTest to point to dev_snapshot_PG18

PR fixes build warning messages on DockerHub and on my local build.

No regression tests needed.

modified:   src/include/nodes/ag_nodes.h
modified:   src/include/optimizer/cypher_createplan.h
modified:   src/include/optimizer/cypher_pathnode.h
modified:   tools/gen_keywordlist.pl

…raph (#2248)

Fixed issue 2245 - Creating more than 41 vlabels causes drop_grapth to fail
with "label (relation) cache corrupted" and crashing out on the following
command.

This was due to corruption of the label_relation_cache during the HASH_DELETE
process.

As the issue was with a cache flush routine, it was necessary to fix them
all. Here is the list of the flush functions that were fixed -

    static void flush_graph_name_cache(void)
    static void flush_graph_namespace_cache(void)
    static void flush_label_name_graph_cache(void)
    static void flush_label_graph_oid_cache(void)
    static void flush_label_relation_cache(void)
    static void flush_label_seq_name_graph_cache(void)

Added regression tests.

modified:   regress/expected/catalog.out
modified:   regress/sql/catalog.sql
modified:   src/backend/utils/cache/ag_cache.c

- Whenever a label will be created, indices on id columns will be
  created by default. In case of vertex, a unique index on id column
  will be created, which will also serve as a unique constraint.
  In case of edge, a non-unique index on start_id and end_id columns
  will be created.

- This change is expected to improve the performance of queries that
  involve joins. From some performance tests, it was observed that
  the performance of queries improved alot.

- Loader was updated to insert tuples in indices as well. This has
  caused to slow the loader down a bit, but it was necessary.

- A bug related to command ids in cypher_delete executor was also fixed.

Resolved conflicts:
	regress/expected/cypher_match.out
	regress/expected/expr.out

)

Fixed issue 2256: A segmentation fault occurs when calling the coalesce
function in PostgreSQL version 17. This likely predates 17 and includes
other similar types of "functions".

See issues 1124 (PR 1125) and 1303 (PR 1317) for more details.

This issue is due to coalesce() being processed differently from other
functions. Additionally, greatest() was found to exhibit the same
behavior. They were added to the list of types to ignore during the
cypher analyze phase.

A few others were added: CaseExpr, XmlExpr, ArrayExpr, & RowExpr.
Although, I wasn't able to find cases where these caused crashes.

Added regression tests.

modified:   regress/expected/cypher.out
modified:   regress/sql/cypher.sql
modified:   src/backend/parser/cypher_analyze.c

Adjusted the following type of error message. It was mentioned in
issue 2263 as being incorrect, which it isn't. However, it did need
some clarification added -

    ERROR:  could not find rte for <column name>

Added a HINT for additional clarity -

    HINT:  variable <column name> does not exist within scope of usage

For example:

    CREATE p0=(n0), (n1{k:EXISTS{WITH p0}}) RETURN 1

    ERROR:  could not find rte for p0
    LINE 3:     CREATE p0=(n0), (n1{k:EXISTS{WITH p0}})
                                              ^
    HINT:  variable p0 does not exist within scope of usage

Additionally, added pstate->p_expr_kind == EXPR_KIND_INSERT_TARGET to
transform_cypher_clause_as_subquery.

Updated existing regression tests.
Added regression tests from issue.

modified:   regress/expected/cypher_call.out
modified:   regress/expected/cypher_subquery.out
modified:   regress/expected/cypher_union.out
modified:   regress/expected/cypher_with.out
modified:   regress/expected/expr.out
modified:   regress/expected/list_comprehension.out
modified:   regress/expected/scan.out
modified:   src/backend/parser/cypher_clause.c
modified:   src/backend/parser/cypher_expr.c

- Used postgres memory allocation functions instead of standard ones.
- Wrapped main loop of csv loader in PG_TRY block for better error handling.

NOTE: This PR was partially created with AI tools and reviewed by a human.

ORDER BY clauses failed when referencing column aliases from RETURN:

    MATCH (p:Person) RETURN p.age AS age ORDER BY age DESC
    ERROR: could not find rte for age

Added SQL-99 compliant alias matching to find_target_list_entry() that
checks if ORDER BY identifier matches a target list alias before
attempting expression transformation. This enables standard SQL behavior
for sorting by aliased columns with DESC/DESCENDING/ASC/ASCENDING.

Updated regression tests.

Added regression tests.
modified:   regress/expected/cypher_match.out
modified:   regress/expected/expr.out
modified:   regress/sql/expr.sql
modified:   src/backend/parser/cypher_clause.c

Consolidated duplicate code, added helper functions, and reviewed
the grammar file for issues.

NOTE: I used an AI tool to review and cleanup the grammar file. I
      have reviewed all of the work it did.

Improvements:

1. Added KEYWORD_STRDUP macro to eliminate hardcoded string lengths
2. Consolidated EXPLAIN statement handling into make_explain_stmt helper
3. Extracted WITH clause validation into validate_return_item_aliases helper
4. Created make_default_return_node helper for subquery return-less logic

Benefits:

- Reduced code duplication by ~150 lines
- Improved maintainability with helper functions
- Eliminated manual string length calculations (error-prone)

All 29 existing regression tests pass

modified:   src/backend/parser/cypher_gram.y

#2267)

- Changed '\s' to r'\s'

- Add pyproject.toml with package configuration
- Simplify setup.py to minimal backward-compatible wrapper.
- Updated CI workflow and .gitignore.
- Resolves warning about using setup.py directly.

This PR applies restrictions to the following age_load commands -

    load_labels_from_file()
    load_edges_from_file()

They are now tied to a specific root directory and are required to have a
specific file extension to eliminate any attempts to force them to access
any other files.

Nothing else has changed with the actual command formats or parameters,
only that they work out of the /tmp/age directory and only access files
with an extension of .csv.

Added regression tests and updated the location of the csv files for
those regression tests.

modified:   regress/expected/age_load.out
modified:   regress/sql/age_load.sql
modified:   src/backend/utils/load/age_load.c