Perl: epoch(now)

perl -MTime::Local -e 'print timegm(gmtime)'

PostgreSQL: size of a row

Source: Measure the size of a PostgreSQL table row

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SELECT l.what, l.nr AS "bytes/ct"      , CASE WHEN is_size THEN pg_size_pretty(nr) END AS bytes_pretty      , CASE WHEN is_size THEN nr / x.ct END          AS bytes_per_row FROM  (    SELECT min(tableoid)        AS tbl      -- same as 'public.tbl'::regclass::oid         , count(*)             AS ct         , sum(length(t::text)) AS txt_len  -- length in characters    FROM   radius_db.radacct t  -- provide table name *once*    ) x  , LATERAL (    VALUES       (true , 'core_relation_size'               , pg_relation_size(tbl))     , (true , 'visibility_map'                   , pg_relation_size(tbl, 'vm'))     , (true , 'free_space_map'                   , pg_relation_size(tbl, 'fsm'))     , (true , 'table_size_incl_toast'            , pg_table_size(tbl))     , (true , 'indexes_size'                     , pg_indexes_size(tbl))     , (true , 'total_size_incl_toast_and_indexes', pg_total_relation_size(tbl))     , (true , 'live_rows_in_text_representation' , txt_len)     , (false, '------------------------------'   , NULL)     , (false, 'row_count'                        , ct)     , (false, 'live_tuples'                      , pg_stat_get_live_tuples(tbl))     , (false, 'dead_tuples'                      , pg_stat_get_dead_tuples(tbl))    ) l(is_size, what, nr);

mod_perl: how to use environment variable

In httpd.conf:

1	PerlSetEnv PG_FLG 1

In mod_perl code:

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sub is_pure_pg {     return exists $ENV{PG_FLG}; }

PostgreSQL: rotate pgbouncer logs

Simplest method: switch to syslog

vi /etc/pgbouncer/pgbouncer.ini

1 2	; logfile = /var/log/pgbouncer.log syslog = 1

psql -p6432 -Upostgres -d pgbouncer -c reload

PostgreSQL: split record returned by function into columns

Source: PostgreSQL function or stored procedure that outputs multiple columns?

1	SELECT a, (func(a)).* FROM table1;

Git: undo push

Source: How to undo (almost) anything with Git

git revert <SHA>