Hi all. On PG-9.3 (no JSONB), For an IMAP-like system; I'm trying to figure
out an effective way to query for "what flags are in use in a folder". A flag
is considered used when one or more messages in that folder has the value=true.
The schema is like this: create table message( folder_id integer not NULL,
is_seenboolean NOT NULL default false, is_replied boolean not null default false
,is_forwarded boolean not null default false, is_deleted boolean not null
default false, is_draft boolean not null default false, is_flagged boolean not
null default false); I need the "flags" to be in the message-table for other
queries to be as efficient as possible (no JOIN'ing), the system contains
millions of messages. create index message_folder_id_deleted_idx ON message(
folder_id) where is_deleted = TRUE; create index message_folder_id_forwarded_idx
ON message(folder_id) where is_forwarded = TRUE; create index
message_folder_id_replied_idxON message(folder_id) where is_replied = TRUE;
create indexmessage_folder_id_seen_idx ON message(folder_id) where is_seen =
TRUE; create index message_folder_id_flagged_idx ON message(folder_id) where
is_flagged= TRUE; create index message_folder_id_draft_idx ON message(folder_id)
whereis_draft = TRUE; select 'is_deleted' from (select * from message where
folder_id= 3 AND is_deleted limit 1) as q UNION select 'is_forwarded' from (
select* from message where folder_id = 3 AND is_forwarded limit 1) as q UNION
select'isreplied' from (select * from message where folder_id = 3 AND is_replied
limit1) as q UNION select 'is_seen' from (select * from message where folder_id
=3 AND is_seen limit 1) as q UNION select 'is_flagged' from (select * from
message wherefolder_id = 3 AND is_flagged limit 1) as q UNION select 'is_draft'
from(select * from message where folder_id = 3 AND is_draft limit 1) as q ;
Are there better ways to do this? Thanks. -- Andreas Joseph Krogh CTO /
Partner - Visena AS Mobile: +47 909 56 963 andreas(at)visena(dot)com
<mailto:andreas(at)visena(dot)com> www.visena.com <https://www.visena.com>
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