[Lazarus] data matrix with thousands of columns

Mark Morgan Lloyd markMLl.lazarus at telemetry.co.uk
Fri Mar 29 19:43:17 CET 2013


Alexander Klenin wrote:
> On Wed, Mar 27, 2013 at 7:18 PM, Andrea Mauri <andrea.mauri.75 at gmail.com> wrote:
>> Il 27/03/2013 16:11, Max Vlasov ha scritto:
>>
>>> CREATE TABLE [Data] (
>>> ... ,
>>> [Row] INTEGER, [Column] INTEGER, [Value] TEXT
>>> ...
>>> )
>> As I answered to Leonardo I tried something like this but I have to insert
>> millions of entries when application is running and this solution will slow
>> enormously the app.
> 
> Alternatively: http://ibexpert.net/ibe/index.php?n=Doc.Array

Also supported by PostgreSQL, although I've not had a chance to 
investigate how compatible the implementations are- I've got no 
immediate intention of attempting to use them.

As a general comment, sometimes populating a table can be done far 
faster with a server-provided program rather than going through SQL. 
Also Postgres doctrine has it that if populating a big table it might 
pay to disable all indexes until the bulk operation is completed.

-- 
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]




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