[Lazarus] What is a TSQLTransaction and why do I need one?

Martin Schreiber mse00000 at gmail.com
Thu Nov 25 08:34:29 CET 2010


On Wednesday, 24. November 2010 20.40:38 Alexsander Rosa wrote:
> But it is transparent to the libpq programmer; why it's not transparent
> with sqldb?
>
It is, with tao_fake set (MSEgui). The different DB's have very different 
transaction models. As Michael writes, sqldb is designed to get the full 
power of all DB's.
Firebird has the ability for 'named transactions'. It is possible to run 
multiple transactions in parallel on a single connection. PostgreSQL does not 
offer this possibility. In PQ there is for every transaction a separate 
connection and even an additional server process AFAIK!
In MSEgui tsqlquery can have different transactions for reading and writing. 
So the longtime read transaction can be a cheap readonly transaction and the 
expensive write transaction must be active a short time only, this saves 
server resources.
I don't know if ZEOS provides the possibility to work with different 
transactions on a single connection.

Martin




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