Cookbook recipe

Character encoding and collation basics

Applies to PostgreSQL 13–17 Last reviewed May 2026 Grounded in source

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Estimated investigation4 min

Scenario

Sorting looks wrong, or you hit "invalid byte sequence for encoding". Encoding and collation decide how text is stored and ordered. Diagnose it Check database encoding and collation: SELECT datname, pg_encoding_to_char(encoding), datcollate, datctype FROM pg_database; Why…

Investigation Path

Sorting looks wrong, or you hit “invalid byte sequence for encoding”. Encoding and collation decide how text is stored and ordered.

Diagnose it

Check database encoding and collation:

SELECT datname, pg_encoding_to_char(encoding), datcollate, datctype
FROM pg_database;

Why it happens

Encoding (usually UTF8) defines which byte sequences are valid text. Collation defines sort/compare order and case rules. A mismatch between client data and server encoding causes byte-sequence errors; collation differences change ORDER BY results.

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Concepts on this page

Sequence Schema
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