This PR addresses a breaking change from the pgx/v5 library upgrade that caused database insertion failures for PostgreSQL when prefer_simple_protocol is enabled. The issue stemmed from time.Month values being incorrectly encoded as strings (e.g., "May") instead of their underlying integer representation.

The solution avoids modifying shared data structures and instead operates at the database driver level. The Dialect function for PostgreSQL in pumps/sql.go has been refactored to manually initialize the database connection using pgx. It intercepts the connection process with an AfterConnect hook to prepend a custom encoding plan to the pgx type map. This new plan ensures that time.Month values are converted to integers before being passed to the database, resolving the serialization conflict. The implementation also preserves the existing timezone handling from the GORM driver to prevent regressions.

To validate the fix, a new integration test, TestSQLWriteData_PreferSimpleProtocol_Month, has been added. This test specifically configures the SQL pump with prefer_simple_protocol: true, writes a record containing a time.Month value, and verifies that it can be successfully persisted and retrieved.

Files Changed Analysis

• go.mod / go.sum: Upgraded github.com/jackc/pgx/v5 to v5.9.1 and updated github.com/stretchr/testify along with other dependencies to resolve the issue and support the new test.
• pumps/sql.go: Contains the core logic. The Dialect function for the postgres case is modified to manually build the *sql.DB connection. This allows for the injection of a custom type encoder for time.Month via an AfterConnect hook before the connection is passed to GORM.
• pumps/sql_test.go: A new test, TestSQLWriteData_PreferSimpleProtocol_Month, is introduced to reproduce the original bug and confirm that the fix correctly handles time.Month serialization with the simple protocol.

Architecture & Impact Assessment

• What this PR accomplishes: It resolves a critical data serialization bug, ensuring analytics data can be reliably written to PostgreSQL with prefer_simple_protocol enabled after the pgx/v5 upgrade.
• Key technical changes introduced:
  • Manual initialization of the PostgreSQL database connection using pgx's stdlib.OpenDB.
  • Injection of a custom EncodePlan into the pgx type map on each new connection to handle time.Month to int conversion.
  • The pre-configured *sql.DB connection pool is passed to the GORM driver, overriding its default connection logic.
• Affected system components: The change is isolated to the SQLPump when configured with a PostgreSQL backend and pumps.sql.postgres.prefer_simple_protocol set to true.
• Data Flow Visualization:

sequenceDiagram
participant App as Tyk Pump
participant GORM
participant PGX Driver
participant PostgreSQL DB

App->>GORM: Write(AnalyticsRecord{Month: time.May})
GORM->>PGX Driver: Execute INSERT
Note over PGX Driver: AfterConnect hook has already
Note over PGX Driver: prepended custom encoder
PGX Driver->>PGX Driver: Encode(time.May) results in int(5)
PGX Driver->>PostgreSQL DB: INSERT INTO tyk_analytics (..., month, ...) VALUES (..., 5, ...)
PostgreSQL DB-->>PGX Driver: Success
PGX Driver-->>GORM: Success
GORM-->>App: Success

## Scope Discovery & Context Expansion
- The fix is narrowly scoped to the PostgreSQL dialect initialization within `pumps/sql.go`. It does not affect other SQL dialects (e.g., MySQL) or other pumps.
- The primary data structure involved is `analytics.AnalyticsRecord`, specifically its `Month time.Month` field.
- By implementing the fix at the database driver level, the solution is transparent to higher-level application logic. This is a significant architectural advantage, as it avoids a broader, potentially breaking change to the `AnalyticsRecord` struct, which could have impacted numerous other Tyk components.


<details>
  <summary>Metadata</summary>

  - Review Effort: 3 / 5
  - Primary Label: bug


</details>
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*Last updated: 2026-04-17T12:06:08.111Z | Triggered by: pr_updated | Commit: a66909a*

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✅ Security Check Passed

No security issues found – changes LGTM.

Architecture Issues (1)

✅ Security Check Passed

No security issues found – changes LGTM.

Architecture Issues (1)

✅ Quality Check Passed

No quality issues found – changes LGTM.

Powered by Visor from Probelabs

Last updated: 2026-04-17T12:06:05.466Z | Triggered by: pr_updated | Commit: a66909a

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Quality Gate failed

Failed conditions 0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

This is misleading. TestSQLWriteData_PreferSimpleProtocol_Month covers and tests the new code.

Quality Gate failed

Failed conditions
0.0% Coverage on New Code (required ≥ 80%)

See analysis details on SonarQube Cloud

Closed this PR to make the QA process easier. The bug only appears with this go.mod file: https://github.com/TykTechnologies/tyk-pump/pull/959/changes#diff-33ef32bf6c23acb95f5902d7097b7a1d5128ca061167ec0716715b0b9eeaa5f6