Example Filter Conditions¶

Return Galaxies¶

…below a redshift of 0.1:

nsa.z < 0.1

…on plates 7815 and 8485:

cube.plate == 7815 or cube.plate == 8485

…with a IFU size of 127:

ifu.name = 127*

…with g-r color < 0.2:

g_r < 0.2

…with Halpha flux > 25 in more than 20% of their good spaxels:

npergood(emline_gflux_ha_6564 > 25) >= 20

…that have an Halpha flux > 25:

emline_gflux_ha_6564 > 25

…that have Halpha EW > 6 in galaxies between stellar mass 9.5-11 with sersic index < 2:

nsa.sersic_logmass >= 9.5 and nsa.sersic_logmass < 11 and nsa.sersic_n < 2 and emline_sew_ha_6564 > 6

…that have NII/Halpha ratio > 0.1:

nii_to_ha > 0.1

emline_gflux_ha_6564 > 25
npergood(spaxelprop.emline_gflux_ha_6564 > 5) >= 20
nsa.sersic_logmass >= 9.5 and nsa.sersic_logmass < 11 and nsa.sersic_n < 2 and emline_sew_ha_6564 > 6
nsa.z < 0.1 and haflux > 25

Query timing exercise post postgres 9.3 config optimization. From a laptop in Baltimore to Utah with explicit queries in remote mode

Query	1st Run (s)	2nd Run (s)	Best of 5 (1 loop)	Best of 5 (10 loops)
Q1	0.3012	0.2375	682 ms per loop	710 ms per loop
Q2	fail	fail
Q3	39.493	10.087	7 s per loop	7.19 s per loop
Q4	1.1662	0.3331	783 ms per loop	810 ms per loop

q = Query(search_filter=p, mode='remote')

# Best of 5 (1 loop)
%timeit -n 1 -r 5 r = q.run()

# Best of 5 (10 loops)
%timeit -n 10 -r 5 r = q.run()

Query timing from pasting the raw SQL into psql at Utah, pre postgres 9.6 config optimization.

Query	1st Run (s)	2nd Run (s)	Best of 5 (1 loop)
Q1	16.994	0.9450	679 ms per loop
Q2	285.67	82.263	30.9 s per loop
Q3	234.72	35.032	33.7 s per loop
Q4	0.7135	0.6954	716 ms per loop

Query timing from pasting the raw SQL into psql at Utah, post postgres 9.6 config optimization + parallel queries

Query	1st Run (s)	2nd Run (s)	Best of 5 (1 loop)
Q1	1.0	0.517	514 ms per loop
Q2	31.123	11.120	8.56 s per loop
Q3	81.319	25.612	25.4 s per loop
Q4	0.588	0.5668	566 ms per loop