Re: Regarding query optimisation (select for update)

On Tue, 2025-07-15 at 15:40 +0530, Durgamahesh Manne wrote:
> We are facing issues with slow running query 
>    SELECT betid, versionid, betdata, processed, messagetime, createdat, updatedat
>    FROM praermabetdata where processed = 'false'
>    ORDER BY betid, versionid LIMIT 200 OFFSET 0 FOR UPDATE;  
>
>                                                          QUERY PLAN
>
--------------------------------------------------------------------------------------------------------------------------------
>  Limit  (cost=0.28..1.89 rows=1 width=78)
>    ->  LockRows  (cost=0.28..1.89 rows=1 width=78)
>          ->  Index Scan using idx_praermabetdata_processed_betid_versionid on praermabetdata  (cost=0.28..1.88 rows=1
width=78)
>                Index Cond: (processed = false)
>
> image.png
>
> Do we have any alternative way to improve the performance?
> Sometimes processed column use true as well as false 

Please provide EXPLAIN (ANALYZE, BUFFERS) output and use "log_lock_waits"
to see if you are hanging behind locks for a longer time.

Yours,
Laurenz Albe