SQL Server Backup and Restore - Simple Talk

Chapter 5: Log Backups
important consideration and, as was demonstrated for full backups in Chapter 3, use of
backup compression can be beneficial. In Chapter 8, we'll compare the backup speeds
and compression ratios obtained for native log backups, versus log backups with native
compression, versus log backups with SQL Backup compression.
Right now, though, we'll just look at the log backup size. Browse to the C:\SQLBackups\
Chapter5\ folder, or wherever it is that you stored the log backup file and simply note the
size of the file. In my case, it was 85 KB.
T-SQL log backups
Now that we have taken a log backup using the GUI method, we'll insert some new rows
into our DatabaseForLogBackups table and then take a second log backup, this time
using a T-SQL script. Rerun DBCC SQLPERF(LOGSPACE)before we start. Since we've only
added a small amount of data, and have performed a log backup, the live log file is still 50
MB in size, and less than 1% full.
Listing 5-6 shows the script to insert our new data; this time we're inserting considerably
more rows into each of the three tables (1,000 into the first table, 10,000 into the second
and 100,000 into the third) and so our subsequent transaction log backup should also be
much larger, as a result.
Notice that we print the date and time after inserting the rows into MessageTable2,
and then use the WAITFOR DELAY command before proceeding with the final INSERT
command; both are to help us when we come to perform some point-in-time restores, in
Chapter 6.
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