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bio website manitou-mail.org/about-dv.php
location Paris, France
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visits member for 2 years, 1 month
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Let's try to share the bits of knowledge gained during those innumerable hours of programming... Nowadays I use mostly PostgreSQL, C++/Qt, Perl, php on Unix servers.


Apr
18
comment Is there a psql equivalent of bash's reverse-search-history?
ctrl-r is normally provided by the readline library. It appears there's an open issue for postgres.app about this.
Apr
16
comment Postgresql not using GIN trigram index when performing non-ASCII LIKE query?
See if you have non-standard cost settings with select name,source,setting from pg_settings where source<>'default' and source<>'override';
Apr
15
comment Unable to Start PostgreSQL. kernel's SHMMAX parameter exceeded you limit
See this: bugzilla.redhat.com/show_bug.cgi?id=1004724 (kernel.shmmax can't be changed inside an lxc container)
Apr
11
comment Adding unsigned 256 bit integers in PostgreSQL
I wouldn't bother unpacking. In any procedural language, you may add the hex characters directly with a loop from right to left with carry propagation. In C, I'd bet any other method would be slower.
Apr
10
comment PostgreSQL, integer arrays, index for equality
The GIN index is certainly best when applicable. When not applicable, the do-it-yourself functional index as I suggested is a useful alternative. I remember cases with large arrays and wide distribution of values when GIN index creation is so slow that it's unusable.
Apr
10
comment PostgreSQL, integer arrays, index for equality
@Alexandros: their hash function for int[] is essentially hash=1; foreach(elt) hash=31*hash+elt. md5 is expected to perform much better in terms of collisions.
Apr
10
revised PostgreSQL, integer arrays, index for equality
fixed column name in example query
Apr
9
answered What is the “last” data that get's backed up, when running pg_dump on a live server?
Apr
9
revised PostgreSQL, integer arrays, index for equality
crypto => pgcrypto+link
Apr
9
answered PostgreSQL, integer arrays, index for equality
Apr
9
answered What does “ERROR: failed to find parent tuple for heap-only tuple at (1192248,5) in table ”fruits“” mean?
Apr
7
reviewed Approve suggested edit on Installing pgcrypto Extension
Apr
4
comment RETURN NEXT in Postgres Function
@Craig: it can't be used in subqueries but constructs like FOR vars in FETCH 10 FROM mycursor LOOP or RETURN QUERY FETCH... are allowed in plpgsql.
Apr
3
answered RETURN NEXT in Postgres Function
Mar
31
reviewed Approve suggested edit on Is it suitable innodb_buffer_pool_size for MySQL Master-Slave
Mar
30
reviewed Approve suggested edit on UPDATE CONCAT without duplicates
Mar
30
reviewed Approve suggested edit on Upstart script in ubuntu for mongodb
Mar
29
comment How to reuse an update trigger for multiple tables in postgresql?
@ypercube: a statement-level trigger with postgres cannot do new.time=now. Quoting the doc: For row-level INSERT and UPDATE triggers only, the returned row becomes the row that will be inserted or will replace...
Mar
28
reviewed Approve suggested edit on How To change the column order?
Mar
27
reviewed Approve suggested edit on Best practices in securing Oracle Standard edition one