Apologies if this question has already been answered, but I was unable to locate a prior answer in the archives...

I have a table with approximately 10 million records, called "indethom", and with an INTEGER column called "clavis" which is set up as a primary key. When I try to perform a select on the table, restricting the result to only the first 100 records, PostgreSQL performs a sequence scan, rather than an index scan (as shown by using EXPLAIN). Needless to say the sequence scan takes forever. Is there some way to get PostgreSQL to use my wonderful indexes? Have I somehow built the indexes incorrectly or something?

Here's the description of the table:

====================== PSQL Output Snip =========================

it=> \d indethom
Table "public.indethom"
Column | Type | Modifiers
numeoper | smallint | not null
nomeoper | character(3) | not null
... (numerous columns skipped) ...
verbum | character varying(22) | not null
poslinop | integer | not null
posverli | smallint | not null
posverop | integer | not null
clavis | integer | not null
articref | integer |
sectref | integer |
query_counter | integer |
Indexes: indethom_pkey primary key btree (clavis),
indethom_articulus_ndx btree (nomeoper, refere1a, refere1b, refere2a, refere2b, refere3a, refere3b),
indethom_sectio_ndx btree (nomeoper, refere1a, refere1b, refere2a, refere2b, refere3a, refere3b, refere4a, refere4b),
it_clavis_ndx btree (clavis),
verbum_ndx btree (verbum)

it=> explain select * from indethom where clavis < 25;
Seq Scan on indethom (cost=0.00..1336932.65 rows=3543991 width=236)
Filter: (clavis < 25)
(2 rows)

================== End Snip =====================

Feel free to point me to any FAQ or previous message that already answers this question. Thanks in advance!

-Erik Norvelle

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