On 08/20/12 11:46 AM, elliott wrote:
> envdb=# \d astgtm2_n60e073;
> Table "public.astgtm2_n60e073"
> Column | Type | Modifiers
> --------+---------+-----------
> lat | real |
> lon | real |
> alt | integer |
> Indexes:
> "q3c_astgtm2_n60e073_idx" btree (q3c_ang2ipix(lon, lat)) CLUSTER
so, you DO have an index. what type does this function
q3c_ang2ipix(real,real) return ? googling it suggested a bigint, which
means every 12 byte (real,real,int) row has a corresponding b-tree entry
of 8 bytes plus b-tree stuff. I see you used cluster on this, did you
do the CLUSTER after populating the table, and before checking the
pg_total_relation_size that you reported as 20X your data ?
--
john r pierce N 37, W 122
santa cruz ca mid-left coast
