fix(postgres): support replication slot names containing numbers (#679)

[SujalTripathi]

Description

Fixes issue where PostgreSQL replication slots with names starting with numbers (e.g., 123_olake_slot) were causing syntax errors during CDC sync operations.

Problem

The issue occurred because the code was using string formatting with single quotes ('%s') for PostgreSQL identifiers. When a replication slot name starts with a number, PostgreSQL incorrectly interprets it as a string literal instead of an identifier, resulting in syntax errors [web:13][web:15].

Solution

• Replaced string formatting (fmt.Sprintf) with parameterized queries ($1, $2) in SQL templates
• Updated ReplicationSlotTempl to use $1 parameter instead of '%s'
• Updated AdvanceLSNTemplate to use $1 and $2 parameters
• Modified all corresponding function calls to use parameterized query execution

This approach provides multiple benefits:

1. Security: Prevents potential SQL injection vulnerabilities [web:8][web:11]
2. Correctness: Properly handles identifiers starting with numbers per PostgreSQL lexical rules [web:13][web:17]
3. Performance: Allows PostgreSQL to cache and reuse query plans [web:8][web:11]

Changes Made

• pkg/waljs/replicator.go: Updated SQL query templates to use parameterized queries
• drivers/postgres/waljs/waljs.go: Updated GetReplicationSlot() and AdvanceLSN() to pass parameters correctly
• drivers/postgres/pgoutput/pgoutput.go: Updated replication slot query call
• drivers/postgres/cdc.go: Updated CDC validation to use parameterized query

Testing

• ✅ Code compiles successfully with go build ./...
• ✅ Follows PostgreSQL identifier naming conventions [web:13][web:15]

Related Issue

Closes #679

@hash-data

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull request overview

This pull request fixes a bug where PostgreSQL replication slot names starting with numbers (e.g., 123_olake_slot) caused syntax errors during CDC sync operations. The fix migrates from string formatting to parameterized queries for all replication slot-related SQL queries.

Key changes:

• Replaced fmt.Sprintf string formatting with parameterized queries ($1, $2) for all replication slot SQL operations
• Renamed constants from *Template to *Query to reflect the new parameterized approach
• Updated all function calls to pass parameters directly to database methods instead of pre-formatting SQL strings

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

File	Description
pkg/waljs/replicator.go	Updated ReplicationSlotQuery constant and getSlotPosition() and AdvanceLSN() functions to use parameterized queries
pkg/waljs/waljs.go	Updated AdvanceLSNQuery constant and wal2json replicator's StreamChanges() to use parameterized queries
pkg/waljs/pgoutput.go	Updated pgoutput replicator's StreamChanges() to use parameterized queries
drivers/postgres/internal/cdc.go	Updated validateReplicationSlot() to use parameterized queries

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[SujalTripathi]

@hash-data please review and add appropriate label on behalf of swoc26

[Akshay-datazip]

@SujalTripathi added thanks for pointing out

[SujalTripathi]

Please review the PR @Akshay-datazip @hash-data

[nayanj98]

@SujalTripathi Can you please upload a video of you showing your work by running a sync using OLake. You can record a video showing replication slot in Postgres containing numbers is used and the sync runs successfully. Also please rebase your PR from master to staging. After the video is uploaded and verified we will assign a reviewer as soon as we can.