### Does this PR have any customer impact?
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
### Are you introducing any new config? If yes, do you have tests with and without them being set?
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
[Composite] Prefer composite indexes over non composite on the planer layer
This implements the get_rel_info_hook and reorders the rel indexlist based on the following ordering:
1. primary key index
2. composite index
3. regular indexes
4. wildcard indexes
5. Any other index
This also renames enableCompositeTerm to enableOrderedIndex option on the metadata options we return to the user
----
#### AI description (iteration 1)
#### PR Classification
Feature enhancement: this PR updates the planner to preferentially use composite indexes over non-composite ones.
#### PR Summary
The pull request implements index ordering logic in the planner to favor composite indexes by introducing new sorting and logging functions, replacing the legacy “enableCompositeTerm” with “enableOrderedIndex”, and updating the associated feature flags and tests.
- **`src/planner/documents_planner.c`**: Added functions (e.g., `GetIndexOptInfoSortOrder`, `CompareIndexOptionsFunc`, and `ExtensionGetRelationInfoHook*`) to prioritize indexes so that composite indexes rank higher.
- **`src/configs/feature_flag_configs.c` and `src/configs/testing_configs.c`**: Introduced new boolean flags (`enableIndexPriorityOrdering` and `logRelationIndexesOrder`) to control the index ordering and logging behavior.
- **`src/metadata/index.c` and `src/commands/create_indexes.c`**: Updated index creation and comparison logic to replace `enableCompositeTerm` with `enableOrderedIndex` for consistent composite index handling.
- **Test files (under `/oss/pg_documentdb/src/test/regress/` and `/pgmongo/src/test/`)**: Revised expected outputs and SQL tests to validate that composite indexes are now preferred in the query planner.
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->
### Does this PR have any customer impact?
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
### Are you introducing any new config? If yes, do you have tests with and without them being set?
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
[oss] Cleanup to conform with contributing guidelines
----
#### AI description (iteration 1)
#### PR Classification
This pull request is a code cleanup that standardizes naming conventions to conform with the contributing guidelines.
### Does this PR have any customer impact?
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
### Are you introducing any new config? If yes, do you have tests with and without them being set?
### ChangeLog (Refer [Template](../oss/CHANGELOG.md))
### Description
3 c files
----
#### AI description (iteration 1)
#### PR Classification
This pull request focuses on code cleanup and documentation updates.
#### PR Summary
The changes standardize and simplify documentation comments and examples across several operator implementations, removing obsolete references and unnecessary details.
- `oss/pg_documentdb/src/aggregation/bson_aggregation_output_pipeline.c`: Updated doc examples for `$merge` and `$out` to use generic placeholders and removed temporary test-related comments.
- `oss/pg_documentdb/src/query/bson_dollar_operators.c`: Cleaned up comments for multiple BSON dollar operators by eliminating "Mongo's" references and redundant test notes.
- `oss/pg_documentdb_core/src/types/pcre_regex.c`: Refined regex compile option comments and removed legacy test reference lines.
<!-- GitOpsUserAgent=GitOps.Apps.Server.pullrequestcopilot -->
### Does this PR have any customer impact?
Yes
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Feature
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
To enable top level query operators working in schema validation.
----
#### AI description (iteration 1)
#### PR Classification
New feature
#### PR Summary
This pull request introduces support for the `$jsonSchema` query operator for schema validation.
- Added handling for `QUERY_OPERATOR_JSONSCHEMA` in `query_operator.c` and `mongo_query_operator.c`.
- Implemented `GetExpressionEvalStateForBsonInput` in `bson_expr_eval.c`.
- Added `BsonJsonSchemaFunctionId` and related OID cache in `metadata_cache.c`.
- Modified `PrepareForSchemaValidation` in `schema_validation.c` to use the new evaluation state function.
### Does this PR have any customer impact?
Yes
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Perf
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
Yes
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Improve performance for a point read set up for unsharded collections.
In the scenario where we have a point read in a local unsharded collection with colocation, we can bypass a lot of the planner and go directly to the PK index. Use this to simplify the planner.
With this change, point reads on YCSB are able to hit ~16k on Marlin and ~17.5-18k on flex
----
#### AI description (iteration 1)
#### PR Classification
New feature
#### PR Summary
Introduces a custom planner for point read operations to optimize query performance.
- Added `documents_custom_planner.c` to implement the custom point read planner.
- Updated `aggregation_commands.c` to handle the new point read cursor type.
- Modified `planner.c` to integrate the custom point read planner and expand aggregation functions.
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactoring
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Remove helio references from documentdb
Remove helio references from documentdb_distributed
----
#### AI description (iteration 1)
#### PR Classification
Code cleanup
#### PR Summary
This pull request removes references to "helio" and replaces them with "documentdb" in the sources of `documentdb` and `documentdb_distributed`.
- `metadata_cache.h` and `metadata_cache.c`: Replaced "Helio" with "DocumentDB" in variable names and function names.
- `pgmongo.c`: Updated include statements and function calls to use "documentdb" instead of "helio".
- `planner.c`: Updated planner function and related calls to use "DocumentDBApiPlanner".
- Moved several header files from `helio_*` to `documentdb_*` naming convention without code changes.
- `commands_common.c` and `create_indexes.c`: Updated function calls and variable names to use "DocumentDB" instead of "Helio".
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactoring
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Remove helio from file name
Remove helio references from source content except schema reference
Start local documentdb server with the documentdb extension
Regression tests using the documentdb extension
----
#### AI description (iteration 1)
#### PR Classification
Code cleanup
#### PR Summary
This pull request removes references to "helio" from the `documentdb_core` source code.
- `scripts/utils.sh`: Renamed variables from `preloadExtensions` to `preloadLibraries`.
- `pg_documentdb_core/include/utils/error_utils.h`: Updated function and macro names to replace "Helio" with "DocumentDB".
- `pg_documentdb_core/include/io/helio_bson_core.h` and `pg_documentdb_core/include/query/helio_bson_compare.h`: Moved to `pg_documentdb_core/include/io/bson_core.h` and `pg_documentdb_core/include/query/bson_compare.h`.
- `pg_documentdb_core/src/collation/collation.c` and `pg_documentdb_core/src/io/pgbson.c`: Replaced error codes and messages to use "DocumentDB" instead of "Helio".
- `scripts/validate_helio_extension_state.sh`: Added exceptions for certain files to skip validation for "helio" references.
### Does this PR have any customer impact?
No
### Type (Feature, Refactoring, Bugfix, DevOps, Testing, Perf, etc)
Refactor
### Does it involve schema level changes? (Table, Column, Index, UDF, etc level changes)
No
### Are you introducing any new config? If yes, do you have tests with and without them being set?
No
### Release Note (Refer [Template](../docs/release_notes/pgmongo_template.md))
### Description
Move source files under new directory.
----
#### AI description (iteration 1)
#### PR Classification
Code reorganization
#### PR Summary
This pull request moves the `helio_api` and `helio_distributed` sources under the `documentdb` directory, updating references and initialization logic accordingly.
- Added `pg_documentdb.c` for initializing the `pg_documentdb` extension.
- Added `documentdb_distributed.c` for initializing the `pg_documentdb_distributed` extension.
- Updated `validate_helio_extension_state.sh` to include new checks for `documentdb`.
- Moved `helio_api_extension_version.c` to `documentdb_extension_version.c` without code changes.
- Updated various `Makefile` configurations to reflect the new directory structure and dependencies.
Santiago Fernandez Madero
Parag Jain
Jia Hu
Vinod Sridharan
Zinan Ren