explain_summary_examples.out.txt
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Filename: explain_summary_examples.out.txt
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postgres=# explain select * from pg_class c, pg_type t where c.reltype = t.oid;
QUERY PLAN
--------------------------------------------------------------------------
Hash Join (cost=17.15..35.77 rows=321 width=511)
Hash Cond: (c.reltype = t.oid)
-> Seq Scan on pg_class c (cost=0.00..14.21 rows=321 width=259)
-> Hash (cost=12.62..12.62 rows=362 width=256)
-> Seq Scan on pg_type t (cost=0.00..12.62 rows=362 width=256)
(5 rows)
postgres=# explain (summary on) select * from pg_class c, pg_type t where c.reltype = t.oid;
QUERY PLAN
--------------------------------------------------------------------------
Hash Join (cost=17.15..35.77 rows=321 width=511)
Hash Cond: (c.reltype = t.oid)
-> Seq Scan on pg_class c (cost=0.00..14.21 rows=321 width=259)
-> Hash (cost=12.62..12.62 rows=362 width=256)
-> Seq Scan on pg_type t (cost=0.00..12.62 rows=362 width=256)
Planning time: 0.326 ms
(6 rows)
postgres=# explain (summary off) select * from pg_class c, pg_type t where c.reltype = t.oid;
QUERY PLAN
--------------------------------------------------------------------------
Hash Join (cost=17.15..35.77 rows=321 width=511)
Hash Cond: (c.reltype = t.oid)
-> Seq Scan on pg_class c (cost=0.00..14.21 rows=321 width=259)
-> Hash (cost=12.62..12.62 rows=362 width=256)
-> Seq Scan on pg_type t (cost=0.00..12.62 rows=362 width=256)
(5 rows)
postgres=# explain analyze select * from pg_class c, pg_type t where c.reltype = t.oid;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------
Hash Join (cost=17.15..35.77 rows=321 width=511) (actual time=0.905..1.357 rows=198 loops=1)
Hash Cond: (c.reltype = t.oid)
-> Seq Scan on pg_class c (cost=0.00..14.21 rows=321 width=259) (actual time=0.010..0.066 rows=321 loops=1)
-> Hash (cost=12.62..12.62 rows=362 width=256) (actual time=0.829..0.829 rows=362 loops=1)
Buckets: 1024 Batches: 1 Memory Usage: 74kB
-> Seq Scan on pg_type t (cost=0.00..12.62 rows=362 width=256) (actual time=0.007..0.425 rows=362 loops=1)
Planning time: 0.328 ms
Execution time: 1.510 ms
(8 rows)
postgres=# explain (summary on, analyze on) select * from pg_class c, pg_type t where c.reltype = t.oid;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------
Hash Join (cost=17.15..35.77 rows=321 width=511) (actual time=0.781..1.224 rows=198 loops=1)
Hash Cond: (c.reltype = t.oid)
-> Seq Scan on pg_class c (cost=0.00..14.21 rows=321 width=259) (actual time=0.009..0.061 rows=321 loops=1)
-> Hash (cost=12.62..12.62 rows=362 width=256) (actual time=0.744..0.744 rows=362 loops=1)
Buckets: 1024 Batches: 1 Memory Usage: 74kB
-> Seq Scan on pg_type t (cost=0.00..12.62 rows=362 width=256) (actual time=0.007..0.358 rows=362 loops=1)
Planning time: 0.333 ms
Execution time: 1.360 ms
(8 rows)
postgres=# explain (summary off, analyze on) select * from pg_class c, pg_type t where c.reltype = t.oid;
QUERY PLAN
----------------------------------------------------------------------------------------------------------------------
Hash Join (cost=17.15..35.77 rows=321 width=511) (actual time=0.783..1.221 rows=198 loops=1)
Hash Cond: (c.reltype = t.oid)
-> Seq Scan on pg_class c (cost=0.00..14.21 rows=321 width=259) (actual time=0.009..0.059 rows=321 loops=1)
-> Hash (cost=12.62..12.62 rows=362 width=256) (actual time=0.745..0.745 rows=362 loops=1)
Buckets: 1024 Batches: 1 Memory Usage: 74kB
-> Seq Scan on pg_type t (cost=0.00..12.62 rows=362 width=256) (actual time=0.007..0.358 rows=362 loops=1)
(6 rows)
postgres=# prepare somestmt as select count(*) from t1 where a > 100;
PREPARE
postgres=# explain (summary on) execute somestmt;
QUERY PLAN
-----------------------------------------------------------
Aggregate (cost=40.13..40.14 rows=1 width=8)
-> Seq Scan on t1 (cost=0.00..38.25 rows=753 width=0)
Filter: (a > 100)
Planning time: 0.245 ms
(4 rows)
postgres=# explain (summary on) execute somestmt;
QUERY PLAN
-----------------------------------------------------------
Aggregate (cost=40.13..40.14 rows=1 width=8)
-> Seq Scan on t1 (cost=0.00..38.25 rows=753 width=0)
Filter: (a > 100)
Planning time: 0.012 ms
(4 rows)
postgres=# alter table t1 add c;
ERROR: syntax error at or near ";"
LINE 1: alter table t1 add c;
^
postgres=# alter table t1 add c int;
ALTER TABLE
postgres=# explain (summary on) execute somestmt;
QUERY PLAN
-----------------------------------------------------------
Aggregate (cost=37.20..37.21 rows=1 width=8)
-> Seq Scan on t1 (cost=0.00..35.50 rows=680 width=0)
Filter: (a > 100)
Planning time: 0.265 ms
(4 rows)
postgres=# explain (summary on) execute somestmt;
QUERY PLAN
-----------------------------------------------------------
Aggregate (cost=37.20..37.21 rows=1 width=8)
-> Seq Scan on t1 (cost=0.00..35.50 rows=680 width=0)
Filter: (a > 100)
Planning time: 0.013 ms
(4 rows)