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08004

PostgreSQL 08004: sqlserver_rejected_establishment_of_sqlconnection

Verified with sources3 sourcesReviewed Aug 23, 2026
Trace

Evidence linked to this decision

View source: PostgreSQL 18 Appendix A: Error Codes

Risk level

Medium

Proceed carefully and stop if the check is unclear.

Urgency

Medium

Quick answer

SQLSTATE 08004 (sqlserver_rejected_establishment_of_sqlconnection) means the PostgreSQL server was reached but rejected creation of the connection. Diagnose the named condition before retrying.

Safety first

Safe checks you can perform

  • Read the server's rejection reason

What a technician must be able to justify

A technician is coming

These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.

These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.

    Before accepting a part or repair

    Nothing has been shown yet. Do not accept a part swap based on the code alone.

    Follow these steps

    Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.

    1. Read the server's rejection reason

      Tools required

      Keep the complete server message and correlate the attempt with PostgreSQL logs. Route capacity messages to pool and connection analysis, startup or recovery messages to readiness, and policy messages to pg_hba.conf or role review; a network retry alone cannot correct a deliberate rejection.

      Evidence: PostgreSQL 18 Appendix A: Error Codes · PostgreSQL error and notice fields · PostgreSQL database connection control functions

    Still not solved

    If the error persists, stop here. See what the technician must do and show you.

    Virtual technician

    Does 08004 still appear after these checks?

    This guided flow uses the exact code and your answers to choose a test, an expected result and the next branch.

    Where this code applies

    A code is meaningful only inside the right product and version context.

    Primary scope

    System
    Software and systems
    Brand
    PostgreSQL
    Product type
    Database

    Known code variants

    • PostgreSQL 08004
    • sqlserver_rejected_establishment_of_sqlconnection
    • SQLSTATE 08004

    What it means

    PostgreSQL assigns 08004 to sqlserver_rejected_establishment_of_sqlconnection in Class 08 — Connection Exception. Applications should branch on the stable SQLSTATE and structured error fields, not localized message text.

    Symptoms and causes

    Probable causes · in order

    • Likely trigger in this requestCommon

      A server-side gate such as connection capacity, startup state or access policy refused the session before it became usable.

      Evidence: PostgreSQL 18 Appendix A: Error Codes · PostgreSQL error and notice fields · PostgreSQL database connection control functions

    Sources and technical references

    1. 1

      PostgreSQL 18 Appendix A: Error Codes

      PostgreSQL Global Development Group · 2026 · official_doc

    2. 2

      PostgreSQL error and notice fields

      PostgreSQL Global Development Group · 2026 · official_doc

    3. 3

      PostgreSQL database connection control functions

      PostgreSQL Global Development Group · 2026 · official_doc

    Sources: PostgreSQL 18 Appendix A: Error Codes · PostgreSQL error and notice fields · PostgreSQL database connection control functionsreviewed 2026-08-23 · verified

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