At 11:20 AM 6/21/00 -0400, Leyne, Sean wrote:

>Jim et all,
>
>Taking your cue, I'd like to review the operation of GBAK.
>
>To start with, what would account for the "sluggish" performance of
>GBAK? Or in other words, what exactly does GBAK do?
>
>In comparison, to say, MSSQL server which can run at speeds (that I've
>seen) of 100-150Mbit per second.
>

Gbak is a non-privileged logical backup utility using the published
API. On backup, gbak first reads system tables, writes an abstract
to the backup file, then loops through each table fetching all fields,
writing data to backup file. If the -t (transportable) switch is
specified, gbak translates all datatypes to a canonical format.
A gbak restore is, in fact, an ordinary database creation followed
by meta-data restore (all indexes, constraints, and triggers are
turned off), data restore, and activation of indexes, constraints,
and triggers. Absolutely no magic at all (well, almost none.
Charlie added an option to defer garbage collection or something
like that).

A physical (page level) backup is almost always faster (much
less processing) but is significantly bigger (indexes are included).

A straight file copy counts as a physical backup. Just be very
careful about multi-file databases.

Jim Starkey