diff options
Diffstat (limited to 'contrib/intarray')
| -rw-r--r-- | contrib/intarray/_int_selfuncs.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/contrib/intarray/_int_selfuncs.c b/contrib/intarray/_int_selfuncs.c index 9bf64486242..ddffd69cb6e 100644 --- a/contrib/intarray/_int_selfuncs.c +++ b/contrib/intarray/_int_selfuncs.c @@ -210,8 +210,8 @@ _int_matchsel(PG_FUNCTION_ARGS) */ if (sslot.nnumbers == sslot.nvalues + 3) { - /* Grab the lowest frequency. */ - minfreq = sslot.numbers[sslot.nnumbers - (sslot.nnumbers - sslot.nvalues)]; + /* Grab the minimal MCE frequency. */ + minfreq = sslot.numbers[sslot.nvalues]; mcelems = sslot.values; mcefreqs = sslot.numbers; @@ -269,8 +269,11 @@ int_query_opr_selec(ITEM *item, Datum *mcelems, float4 *mcefreqs, else { /* - * The element is not in MCELEM. Punt, but assume that the - * selectivity cannot be more than minfreq / 2. + * The element is not in MCELEM. Estimate its frequency as half + * that of the least-frequent MCE. (We know it cannot be more + * than minfreq, and it could be a great deal less. Half seems + * like a good compromise.) For probably-historical reasons, + * clamp to not more than DEFAULT_EQ_SEL. */ selec = Min(DEFAULT_EQ_SEL, minfreq / 2); } |