Hello:

I have an application in Delphi installed in a network with the following data:

Server:
Athlon - 1.29GHz - 1GB RAM
Windows Server 2003
Firebird 2.1.3.18185 SuperServer

Clients (10):
Windows XP

Databases: One of 1.6GB and two smaller than 10MB

They use the application since many years ago without problems. But since the last week they have problems when they connect to some databases or when they make some querys. When they have these problems, I can see that the process fbserver.exe is consuming a lot of memory.

I found in firebird.log (in the server) messages like the following:

Allocated 1729 page buffers of 2048 requested

unable to allocate memory from operating system

Investigating in internet and in this forum, I found this may be related with large querys using blob fields. I am almost sure this is the problem because a few days ago they began to use an option which makes a query like the following:

SELECT TIPCLASNRO
,FECHA
,SUBSTRING(COALESCE(NOTASCOM,'') FROM 1 FOR 100) AS NOTASC
FROM VPRESUP

The field NOTASCOM is a blob field and table VPRESUP have more than 20000 records.

They never need the whole field. They always use SUBSTRING. So I thougt to do the following:

SELECT TIPCLASNRO
,FECHA
,SUBSTRING(COALESCE(CAST(NOTASCOM AS CHAR(32000)),'') FROM 1 FOR 100) AS NOTASC
FROM VPRESUP

This works good because I saw in task manager that the first query uses a lot of memory and the second one practically does not use memory.

But (there is always a but!), this is perfect only if I am sure there is no register with more than 32000 bytes in NOTASCOM. If this is not true, Fireberd returns an error message about string truncation and this does not work.

Does anyone have any idea to suggest?

Thanks in advance

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