PostgreSQL version:

track_activity_query_size

Specifies the number of bytes reserved to track the currently executing command for each active session, for the pg_stat_activity.query field. The default value is 1024. This parameter can only be set at server start.

Recommendations

Sets the truncation threshold of queries in pg_stat_activity (and pg_stat_statements). Increase it if you have really long queries which are being cut off, but there is significant extra memory usage for keeping longer queries.

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