Postgresql

Importing dumps into Cloud SQL without errors: DEFINER and SUPER (ERROR 1227) on MySQL, extensions and owners on PostgreSQL

MySQL: mysqldump –hex-blob –single-transaction –set-gtid-purged=OFF –default-character-set=utf8mb4; DEFINER clauses for users that do not exist on the instance (or root@localhost) break the import. PostgreSQL: pg_dump –format=plain –no-owner –no-acl plus sed to comment out DROP/CREATE/COMMENT ON EXTENSION. Instance service account with objectAdmin on the bucket; gcloud sql import sql with –database and –user.

Oracle CQN with Python: learn about table changes without polling (and why oracle_fdw fires no triggers)

GRANT CHANGE NOTIFICATION; oracledb.connect(events=True); conn.subscribe(callback, operations, qos); sub.registerquery(‘select id, status from orders’). No polling. The database must be able to connect to your app (or use client_initiated=True with Instant Client 19.4+).

pgbouncer: 'unsupported startup parameter: extra_float_digits' (and 'no such database')

ignore_startup_parameters = extra_float_digits, options in pgbouncer.ini and RELOAD. extra_float_digits can be ignored with no consequences; ‘options’ (search_path) cannot: set it on the role with ALTER ROLE SET. ’no such database’ means the entry is missing from [databases] or the * wildcard.

PostgreSQL: admin cheat sheet (rows per table, sizes, sessions, read-only user)

Exact per-table count with the xpath trick, estimate with pg_stat_user_tables, pg_size_pretty for sizes, pg_terminate_backend or DROP DATABASE WITH (FORCE) for sessions, and GRANT pg_read_all_data for the reporting user.