Issue 4130 similaritySearch throwing Exception due to schema name fix

[wilocu]

#4130

Problem
When using PgVectorStore with schema names containing hyphens (e.g., demo-1998), similaritySearch() operations would throw SQL grammar exceptions due to
unquoted PostgreSQL identifiers in generated SQL.

Solution

• Added proper PostgreSQL identifier quoting in getFullyQualifiedTableName() to generate "schema"."table" format
• Updated schema creation DDL to use quoted schema names
• Enhanced schema validator to accept hyphenated names while maintaining security against SQL injection
• Updated error messages to show proper quoted syntax in help text

Changes

• PgVectorStore.java: Fixed SQL generation to use quoted identifiers
• PgVectorSchemaValidator.java: Updated validation logic and error messages
• PgVectorStoreSchemaQuotingTest.java: Added test coverage for hyphenated schema names

Example

Before (❌ SQL error):
SELECT * FROM demo-1998.vector_store -- Syntax error

After (✅ Valid PostgreSQL):
SELECT * FROM "demo-1998"."vector_store" -- Works correctly

Testing

• All existing tests pass
• New test verifies proper quoting for hyphenated schema names
• Verified SQL generation produces valid PostgreSQL syntax

Signed-off-by: Mattia Pasetto [email protected]

I am still pretty new to contributions, please double check and let me know of any errors.