--- Richard Huxton <dev@xxxxxxxxxxxx> wrote:
> Phoenix Kiula wrote:
> > CREATE INDEX idx_trades_tid_partial ON trades (trader_id)
> > WHERE trader_id ~ '[a-z]' ;
>
> > WHERE trader_id = 'johndoe'
> >
> > It is not using this index at all! It is using no index in fact, it's
> > trying to do a sequential scan. Any ideas why this partial index is
> > not working??
> A partial index will only be considered if you test for its condition:
>
> SELECT ... WHERE trader_id = 'johndoe' AND trader_id ~ '[a-z]'
IIRC, for any index like this to work, doesn't the REGEXP need to be anchored to either the start
or end of the string?
Regards,
Richard Broersma Jr.
---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
choose an index scan if your joining column's datatypes do not
match
