Does using BLOBs affect performance versus not using?

[Joe Sansalone]

I'm currently running a phone application where Interbase is used for
the data but not the audio files (typically used for voicemail and/or
prompts etc).

My question is: If I store all audio files in Interbase, will this affect
the current performance?

In other words, when retieving or inserting a BLOB, does this "block" or
slow down other SQL statements?

I currently lookup the file name of the audiofile from Interbase. And then
play it accessing it
directly from a folder.

Joe

[Bill Todd [TeamB]]

Joe Sansalone wrote:

> My question is: If I store all audio files in Interbase, will this
> affect the current performance?

That is difficult to answer without knowing what you mean by "current
performance". Storing blobs in the database will make the database
larger. That will increase the time to backup and restore the database.

Storing the blobs in the database will not increase the time to select
a record if you do not include the blob field in the SELECT clause. It
will increase the time if you do include the blob field in the SELECT
clause but that is comparing apples and oranges. The correct question
is, will the sum of the time to select a record from a database that
does not include the blob plus the time to read the blob from a
separate file on disk exceed the time required to select the record,
including the blob field, from a database that contains the blobs? The
only way to find out is to test.

--
Bill Todd (TeamB)

[Joe Sansalone]

Thanks. That's what I thought ... need to test.

"Bill Todd [TeamB]" <n...@no.com> wrote in message
news:488fd78c$1...@newsgroups.borland.com...

[Wayne Niddery (TeamB)]

"Joe Sansalone" <j...@project1.ca> wrote in message
news:488fd474$1...@newsgroups.borland.com...

>
> In other words, when retieving or inserting a BLOB, does this "block" or
> slow down other SQL statements?

Interbase is multi-threading, so generally no. Blobs are also kept in
separate pages from the rest of the record data, so generally there can only
be contention when 2 or more queries are reading or writing blob data, but
even then only if they are both trying to write to the same page.

The only real issue is as Bill mentions - larger database, longer
backup/restore times.

--
Wayne Niddery - TeamB (www.teamb.com)
Winwright, Inc. (www.winwright.ca)