On Mon, Feb 23, 2009 at 5:27 PM, Gregory Stark <st...@enterprisedb.com>wrote:
> Farhan Husain <russ...@gmail.com> writes: > > > I can provide any other information needed and also the data if anyone > > wants. > > What did the query plans look like in both databases? > > In Postgres you can get the query plan with > > EXPLAIN ANALYZE select ... > > You can leave out the ANALYZE if you can't wait until the query completes > but > it will have much less information to diagnosis any problems. > > -- > Gregory Stark > EnterpriseDB http://www.enterprisedb.com > Ask me about EnterpriseDB's Slony Replication support! > Here is the output: ingentadb=# EXPLAIN ANALYZE select A0.Subj, A2.Obj From jena_g1t1_stmt A0, jena_g1t1_stmt A1, jena_g1t1_stmt A2 Where A0.Prop='Uv:: http://prismstandard.org/namespaces/1.2/basic/isPartOf' AND A0.Obj='Uv:: http://www.utdallas.edu/~farhan.husain/IngentaConnect/issue1_1' AND A0.GraphID=1 AND A0.Subj=A1.Subj AND A1.Prop='Uv:: http://www.w3.org/1999/02/22-rdf-syntax-ns#type' AND A1.Obj='Uv:: http://metastore.ingenta.com/ns/structure/Article' AND A1.GraphID=1 AND A0.Subj=A2.Subj AND A2.Prop='Uv:: http://prismstandard.org/namespaces/1.2/basic/startingPage' AND A2.GraphID=1; QUERY PLAN ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Merge Join (cost=652089.37..665004.47 rows=733195 width=134) (actual time=5410683.129..5410690.033 rows=30 loops=1) Merge Cond: ((a0.subj)::text = (a1.subj)::text) -> Sort (cost=86716.91..86796.78 rows=31949 width=208) (actual time=76.395..76.423 rows=30 loops=1) Sort Key: a0.subj Sort Method: quicksort Memory: 24kB -> Nested Loop (cost=0.00..84326.57 rows=31949 width=208) (actual time=4.146..65.409 rows=30 loops=1) -> Index Scan using jena_g1t1_stmt_ixo on jena_g1t1_stmt a0 (cost=0.00..5428.34 rows=487 width=74) (actual time=1.980..2.142 rows=30 loops=1) Index Cond: ((obj)::text = 'Uv:: http://www.utdallas.edu/~farhan.husain/IngentaConnect/issue1_1'::text) Filter: (((prop)::text = 'Uv:: http://prismstandard.org/namespaces/1.2/basic/isPartOf'::text) AND (graphid = 1)) -> Index Scan using jena_g1t1_stmt_ixsp on jena_g1t1_stmt a2 (cost=0.00..161.37 rows=51 width=134) (actual time=2.101..2.104 rows=1 loops=30) Index Cond: (((a2.subj)::text = (a0.subj)::text) AND ((a2.prop)::text = 'Uv:: http://prismstandard.org/namespaces/1.2/basic/startingPage'::text)) Filter: (a2.graphid = 1) -> Sort (cost=565372.46..568084.16 rows=1084680 width=74) (actual time=5410606.604..5410606.628 rows=31 loops=1) Sort Key: a1.subj Sort Method: quicksort Memory: 489474kB -> Seq Scan on jena_g1t1_stmt a1 (cost=0.00..456639.59 rows=1084680 width=74) (actual time=0.043..44005.780 rows=3192000 loops=1) Filter: ((graphid = 1) AND ((prop)::text = 'Uv:: http://www.w3.org/1999/02/22-rdf-syntax-ns#type'::text) AND ((obj)::text = 'Uv::http://metastore.ingenta.com/ns/structure/Article'::text)) Total runtime: 5410691.012 ms (18 rows) -- Mohammad Farhan Husain Research Assistant Department of Computer Science Erik Jonsson School of Engineering and Computer Science University of Texas at Dallas
