Can the dump history file be used to resolve concurrent backup issues?

Hello,

In Adaptive Server Enterprise 15.7 ESD #2> New Features Guide Adaptive Server Enterprise 15.7 ESD #2> Chapter 9: Concurrent dump database and dump transaction Commands, it is mentioned that

"It may be difficult to determine whether a transaction log you dumped with dump tran precedes the database dump (in which case it need not be loaded), or occurs after the database dump (in which case it should be loaded). Use the dump history file to resolve questions of precedence by including the transaction log or not, as appropriate."

So it appears that the dump history file contains the information related to which transaction log dump belongs to which full dump.

However, by following the testing procedure in this article (Test of Enhancements to Dump and Load in ASE15.7 ESD#2 - Sybase), I found out that the first timestamp in each line of the history file shows the last log dump time for full/log dump, and the third timestamp shows the start time of the full/log dump.

Since there is no timestamp showing the dump instant for a full dump, my questions are: how is the history file useful in resolving the potential issues with concurrent full and transaction log dumps? And how is sybrestore tool able to resolve this?

The steps that I followed are below:

1. First create a table test_table in database ali_db_1, and add a row at 12:02PM. So 12:02 is the last modification time for this database.

1. Do a full dump which starts at 12:03:16 and completes at 12:03:18. Dump instant (from the backup server log) is 12:03:18.

1. Now, see what dumphist looks like. The first timestampshows the last transaction log dump time (Mar 3 1:18:27). The 3^rd timestamp shows the time full dump started.

2|4|ali_db_1|2|Mar  3 2015  1:18:27:980PM|Mar  3 2015 1:18:27:980PM|Mar 10 2015 12:03:15:596PM|/opt/sybsp103/tempdump/ali_db_1.DB.20150310.120316.000|4863|*|0|0|1

1. Add another row in the table at 12:06PM.

1. Add another row in the table at 12:07PM. So 12:07 is the last modification time for this database.

1. Do a transaction log dump which starts at 12:08:21 and finishes at the same second.

1. Now, see what dumphist looks like. The first timestamp shows the last transaction log dump time (Mar 3 1:18:27). The 3^rd timestamp shows the time log dump started.

3|4|ali_db_1|2|Mar  3 2015  1:18:27:980PM|Mar 10 2015 12:08:21:183PM|Mar 10 2015 12:08:21:183PM|/opt/sybsp103/tempdump/ali_db_1.TRAN.20150310.120821.000|0|*|0|0|1

1. Add another row in the table at 12:10PM. So 12:10 is the last modification time for this database.

1. Do another log dump which starts at 12:10:44 and finishes at the same second.

1. Now, see what dumphist looks like. The first timestamp shows the last log dump time (12:08:21PM). The 3^rd timestamp shows the time log dump started.

3|4|ali_db_1|2|Mar 10 2015 12:08:21:183PM|Mar 10 2015 12:10:44:753PM|Mar 10 2015 12:10:44:753PM|/opt/sybsp103/tempdump/ali_db_1.TRAN.20150310.121044.000|0|*|0|0|1