Reindex

REINDEX IN Postgres

https://www.postgresql.org/docs/9.4/sql-reindex.html

REINDEX DATABASE foo;

REINDEX TABLE foo

delete from ids where table_name='item_tag' and nextid=212870;

Get reindex status

short

SELECT * FROM pg_stat_progress_create_index;

Long

SELECT 
  now()::TIME(0), 
  a.query, 
  p.phase, 
  p.blocks_total, 
  p.blocks_done, 
  p.tuples_total, 
  p.tuples_done,
  ai.schemaname,
  ai.relname,
  ai.indexrelname
FROM pg_stat_progress_create_index p 
JOIN pg_stat_activity a ON p.pid = a.pid
LEFT JOIN pg_stat_all_indexes ai on ai.relid = p.relid AND ai.indexrelid = p.index_relid;

Cancel reindex

• https://stackoverflow.com/questions/28969919/postgresql-reindex-still-working-even-after-two-hours

SELECT query, pid FROM pg_stat_activity;
SELECT pid, datname, usename, query FROM pg_stat_activity;
SELECT pg_cancel_backend(774);

https://serverfault.com/questions/35332/what-do-i-do-when-pg-cancel-backend-doesnt-work

Blocked

• https://wiki.postgresql.org/wiki/Lock_Monitoring

 SELECT blocked_locks.pid     AS blocked_pid,
         blocked_activity.usename  AS blocked_user,
         blocking_locks.pid     AS blocking_pid,
         blocking_activity.usename AS blocking_user,
         blocked_activity.query    AS blocked_statement,
         blocking_activity.query   AS current_statement_in_blocking_process,
         blocked_activity.application_name AS blocked_application,
         blocking_activity.application_name AS blocking_application
   FROM  pg_catalog.pg_locks         blocked_locks
    JOIN pg_catalog.pg_stat_activity blocked_activity  ON blocked_activity.pid = blocked_locks.pid
    JOIN pg_catalog.pg_locks         blocking_locks
        ON blocking_locks.locktype = blocked_locks.locktype
        AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
        AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
        AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
        AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
        AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
        AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
        AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
        AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
        AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
        AND blocking_locks.pid != blocked_locks.pid

    JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
   WHERE NOT blocked_locks.GRANTED;