Add ability to backup/restore only those (several) tables which are enumerated as command line argument (pattern) [CORE5538]

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Submitted by: @pavel-zotov

Assigned to: @aafemt

Votes: 1

gbak -? 2>&1 | findstr /i /c:"skip"

\-SKIP\_D\(ATA\) <pattern\> skip data for all tables which are specified in

the <pattern>

This command switch is useful when we want to skip SEVERAL but leave DOZEN of tables, but it does NOT allow to solve opposite task: when we need to b/r only several tables of their huge total number.
Please consider to implement command-line switch like this:

\-SKIP\_E\(CEPT\) <pattern\> skip data for all tables EXCEPT those which are specified in the <pattern\>

-- where <pattern> must follow SIMILAR_TO logic and rules.

Commits: 46102b6 8a8d778

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Commented by: Sean Leyne (seanleyne)

It seems that you are trying to describe something more along the lines of "Backup_Only", correct?

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Commented by: @pavel-zotov

> It seems that you are trying to describe something more along the lines of "Backup_Only", correct?

May be :-)
Sorry, my English knowledge is poor: what does it mean "along the lines" here ?

PS.
"backup_only" plus "restore_only" - two different keys; it seems to me that it will be better to use only one, with "unified" form.

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Commented by: Sean Leyne (seanleyne)

Your point about backup vs. restore is very valid, hadn't considered that.

While I think further about the correct label/name...

What would be the consequence of using both SKIP_DATA and SKIP_EXCEPT at the same time, and where a table name meets both criteria? Would the table be processed?

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Commented by: Sean Leyne (seanleyne)

I think I have syntax/options which would allow for complete control:

- "Data_Exclude" -- Replacement for current "SKIP_DATA"
- "Data_Include" -- companion to the "Data_Exclude", to allow for exceptions to broad "Exclude" filter criteria to be overridden.

{Actually the Exclude/Include options could be used as required to best define the tables to be processed}

The precedence/processing order of the options would be as follows:

If tablename match found in "Data\_Include" then
  table is processed
else If tablename match NOT found in "Data\_Exclude" then
  table is processed
else
  table is skipped

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Commented by: @asfernandes

As skip_data is a regexp, can't it already be used for both (skip, no-skip) purposes?

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Modified by: @AlexPeshkoff

assignee: Alexander Peshkov [ alexpeshkoff ]

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Commented by: @AlexPeshkoff

May be it can be used for both purposes - but special switch is simpler and cleaner for most users

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Commented by: Sean Leyne (seanleyne)

Alexander is correct, the regexp required to handle exclude is anything but straight-forward (I thought so, but my research found it is not).

Separate switch would be the easiest to use.

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Commented by: @pavel-zotov

> As skip_data is a regexp, can't it already be used for both (skip, no-skip) purposes?

Unfortunately, this key can be used only for SKIP, but not for preserve. This is because we can not use in command line (i.e. gfix switch) somewhat like "NOT similar to <pattern>".

Consider following:

recreate table tnames(s varchar(31));
insert into tnames(s) values('anna');
insert into tnames(s) values('beta');
insert into tnames(s) values('ciao');
insert into tnames(s) values('cola');
insert into tnames(s) values('dina');
insert into tnames(s) values('doca');
insert into tnames(s) values('docb');
insert into tnames(s) values('docc');
insert into tnames(s) values('dora');
insert into tnames(s) values('dura');
insert into tnames(s) values('omen');
insert into tnames(s) values('opel');
insert into tnames(s) values('mail');
insert into tnames(s) values('rose');
commit;

How can we select all rows EXCEPT three: 'doca', 'docb' and 'docc' - and at the same time avoid using of logical negation ("NOT') ?

This:

select s
from tnames n
where n.s similar to '(doc)%'; -- includes all names that start with 'doc', this is expected.

But this:

select s
from tnames n
where n.s similar to '[^(doc)]%'; -- excludes all names which start with: 'd', 'o' or 'c'.

It's NOT the same as one may to expect: grouping of three characters: "(" and ")" -- seems to not work here.

[firebird-automations]

Commented by: @pavel-zotov

BTW: is it possible to back-port this feature to 2.5.x ?

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Commented by: Sean Leyne (seanleyne)

Pavel,

Your comment is in the wrong context. The feature is about handling/processing of Tables, not rows!

The excluding of rows is a completely different subject. (it also would not get my vote!)

[firebird-automations]

Commented by: @pavel-zotov

Sean,

consider table names as rows from rdb$relations, please. It is rdb$relations which is used by gbak when we apply '-skip' command switch (AFAIU).
So, why you said that this context is wrong ?

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Commented by: Sean Leyne (seanleyne)

Pavel,

How was I to expect that I needed to "consider table names as rows from rdb$relations"?

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Commented by: @pavel-zotov

me wrong :-)
I should provide more obvoius name instead of "table tnames(s varchar(31));"

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Modified by: @aafemt

assignee: Alexander Peshkov [ alexpeshkoff ] => Dimitry Sibiryakov [ aafemt ]

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Commented by: @aafemt

Mostly it should be a copy-paste of code handling -SKIP_DATA switch.

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Modified by: @aafemt

status: Open [ 1 ] => Open [ 1 ]

Target: 3.0.6 [ 10889 ]

Implementation: [Trivial]

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Modified by: @aafemt

status: Open [ 1 ] => In Progress [ 3 ]

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Modified by: @aafemt

Target: 3.0.6 [ 10889 ] => 4.0 Beta 2 [ 10888 ]

status: In Progress [ 3 ] => In Progress [ 3 ]

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Modified by: @aafemt

status: In Progress [ 3 ] => Open [ 1 ]

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Commented by: @aafemt

Pull request to master branch created.

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Modified by: @aafemt

status: Open [ 1 ] => Resolved [ 5 ]

resolution: Fixed [ 1 ]

Fix Version: 4.0 Beta 2 [ 10888 ]

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Modified by: @pavel-zotov

status: Resolved [ 5 ] => Resolved [ 5 ]

QA Status: No test => Done successfully

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Modified by: @pavel-zotov

status: Resolved [ 5 ] => Closed [ 6 ]