Comments on: Introduction to generating JSON using PostgreSQL

By: Sleeba Paul

Sleeba Paul — Wed, 30 Jan 2019 09:07:07 +0000

You randomly hit to a tutorial, find `hsps` in a code block, then you look again who is the author and you find it is written by your senior. Nice vibe!

By: vijay k

vijay k — Fri, 19 Jan 2018 11:53:00 +0000

–>Here I need order by of CLAIM_COUNTER .
If i put inside json_agg it was not working.
please tell me any other alternative for this one.
SELECT array_to_json(array_agg(Result))
FROM (
SELECT
C.eCPClaim_carrier_id,
json_agg(
row_to_json(
(
SELECT t FROM
(
SELECT C.eCPClaim_Key AS CLAIM_KEY,
(
SELECT eCPClaim_Custom_Value1
FROM tbl_eCPClaim_Custom
WHERE eCPClaim_Key = C.eCPClaim_Key
AND eCPClaim_Custom_Field_Config_ID = ‘text3’
LIMIT 1
) AS CLAIM_COUNTER
ORDER BY CLAIM_COUNTER
) AS t
)
)
) AS available_codes
FROM tbl_ecpclaim C
GROUP BY C.eCPClaim_carrier_id
LIMIT 10
) AS result;

By: vijay k

vijay k — Fri, 19 Jan 2018 06:59:00 +0000

SELECT array_to_json(array_agg(Result))
FROM
(
column 1 ,column 2 ,
json_agg(
row_to_json(
(
SELECT t FROM (
column 3 ,
column 4
—————> here I need order by (column 4 )
)
)
)
) as detils
from table_name
)as result

By: Bowen Masco

Bowen Masco — Mon, 05 Dec 2016 15:29:00 +0000

I cant remember what version of postgres we were using. It might have been an older one. We just moved the json generation back to the app servers. It works there. The database was probably about the same order of magnitude number of records. I would just recommend monitoring the database memory usage. It is possible there was some bug that we ran into that has since been fixed or there was something pathological about our queries. I did not really investigate too deeply since we were just testing it out. It was easy for us to switch back and we had a lot of higher priority stuff we needed to do.

By: Harisankar P S

Harisankar P S — Mon, 05 Dec 2016 05:37:00 +0000

Any idea regarding it. We are using Postgres 9.5 with JSON generation in a table with presently half a million record and growing per day. The query runs in a small subset of the table after joining with other tables, but we have found no spike in memory compare to the spike we see while doing it in rails.
Also what did you do instead. Did you find another suitable/efficient solution for your problem.

By: Bowen Masco

Bowen Masco — Sat, 03 Dec 2016 16:26:00 +0000

It was several months ago and we already moved away from using it.

By: Harisankar P S

Harisankar P S — Sat, 03 Dec 2016 05:34:00 +0000

Can you tell me the type of query that you ran and the number of records in the table. I would like to help you debug and reduce the memory usage.

By: Bowen Masco

Bowen Masco — Thu, 01 Dec 2016 21:34:00 +0000

The problem I ran into was memory consumption on the database server skyrocketed. It slowed down all the other queries. So make sure and profile speed and memory usage for your workload

By: Overbryd

Overbryd — Thu, 01 Dec 2016 20:16:00 +0000

As seen in 2013 (with performance benchmarks): https://hashrocket.com/blog/posts/faster-json-generation-with-postgresql

By: Harisankar P S

Harisankar P S — Sat, 26 Nov 2016 09:50:00 +0000

I did this in production. I saw 4x improvement in request per seconds. Though it’s not a proper benchmark. As it was just a use case for us. I feel that as the JSON data gets more complicated PostgreSQL is a faster alternative.