On Tue, Apr 5, 2011 at 3:25 PM, Maria L. Wilson <Maria.L.Wilson-1@xxxxxxxx> wrote: > Would really appreciate someone taking a look at the query below.... Thanks > in advance! > > > this is on a linux box... > Linux dsrvr201.larc.nasa.gov 2.6.18-164.9.1.el5 #1 SMP Wed Dec 9 03:27:37 > EST 2009 x86_64 x86_64 x86_64 GNU/Linux > > explain analyze > select MIN(IV.STRTDATE), MAX(IV.ENDDATE) > from GRAN_VER GV > left outer join INVENTORY IV on GV.GRANULE_ID = IV.GRANULE_ID, INVSENSOR > INVS > where IV.INV_ID='65' and GV.GRANULE_ID = INVS.granule_id and > INVS.sensor_id='13' > > > "Aggregate (cost=736364.52..736364.53 rows=1 width=8) (actual > time=17532.930..17532.930 rows=1 loops=1)" > " -> Hash Join (cost=690287.33..734679.77 rows=336949 width=8) (actual > time=13791.593..17323.080 rows=924675 loops=1)" > " Hash Cond: (invs.granule_id = gv.granule_id)" > " -> Seq Scan on invsensor invs (cost=0.00..36189.41 rows=1288943 > width=4) (actual time=0.297..735.375 rows=1277121 loops=1)" > " Filter: (sensor_id = 13)" > " -> Hash (cost=674401.52..674401.52 rows=1270865 width=16) (actual > time=13787.698..13787.698 rows=1270750 loops=1)" > " -> Hash Join (cost=513545.62..674401.52 rows=1270865 > width=16) (actual time=1998.702..13105.578 rows=1270750 loops=1)" > " Hash Cond: (gv.granule_id = iv.granule_id)" > " -> Seq Scan on gran_ver gv (cost=0.00..75224.90 > rows=4861490 width=4) (actual time=0.008..1034.885 rows=4867542 loops=1)" > " -> Hash (cost=497659.81..497659.81 rows=1270865 > width=12) (actual time=1968.918..1968.918 rows=1270750 loops=1)" > " -> Bitmap Heap Scan on inventory iv > (cost=24050.00..497659.81 rows=1270865 width=12) (actual > time=253.542..1387.957 rows=1270750 loops=1)" > " Recheck Cond: (inv_id = 65)" > " -> Bitmap Index Scan on inven_idx1 > (cost=0.00..23732.28 rows=1270865 width=0) (actual time=214.364..214.364 > rows=1270977 loops=1)" > " Index Cond: (inv_id = 65)" > "Total runtime: 17533.100 ms" > > some additional info..... > the table inventory is about 4481 MB and also has postgis types. > the table gran_ver is about 523 MB > the table INVSENSOR is about 217 MB > > the server itself has 32G RAM with the following set in the postgres conf > shared_buffers = 3GB > work_mem = 64MB > maintenance_work_mem = 512MB > wal_buffers = 6MB > > let me know if I've forgotten anything! thanks a bunch!! Late response here, but... Is there an index on invsensor (sensor_id, granule_id)? If not, that might be something to try. If so, you might want to try to figure out why it's not being used. Likewise, is there an index on gran_ver (granule_id)? -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
