Conditional row grained replication with DBMirror

[Achilleus Mantzios]

I made a modification on DBMirror.pl,
an addition in the slavedatabase.conf file,
and added another replication table "specialtables".

The goal was to have a way of controlling
when a row of table (if the table is present in specialtables),
will be mirrored to the remote slave.

Lets assume, we have a bank's central IT DEPT master DB
and some branches abroad.

Rows in some tables (e.g. personel, branches, statistics on transactions,
etc...)
have no reason to be replicated to all sites, but only
those sites that these rows refer to:

E.G.
we have
test=# \d personel
Table "public.personel"
Column | Type | Modifiers
---------------+------------------------+-----------
id | integer | not null
name | character varying(20) |
branchid | integer |
test=#

or
test=# \d branch
Table "public.personel"
Column | Type | Modifiers
---------------+------------------------+-----------
id | integer | not null
country | character varying(20) |
address | text |
test=#

And we require that insert, updates on table branch with id = 1
go only to remote site (the ip of) branch 1,
and that inserts,updates on personel with branchid = 2,
in the same fashion, go only to (the ip of) branch 2.

I retain the table specialtables
test=# \d specialtables
Table "public.specialtables"
Column | Type | Modifiers
---------------+------------------------+-----------
tblname | character varying(100) | not null
siteidkeyname | character varying(20) |
Indexes: specialtables_pkey primary key btree (tblname)

test=#

in which for each conditional table, the corresponding
column name (the value of siteidkeyname) is given
which indicates against which column in the PendingData.Data
column is to be examined for equality against the site id.

The site id for each slave is defined in an additional field
in slaveInfo struct in slavedatabase.conf.

Please tell me if i should send the patches
to DBMirror.pl, MirrorSetup.sql, and slavedatabase.conf.

--
================================================== ================
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
Nikis 4, Glyfada
Athens 16610
Greece
tel: [phone]
fax: [phone]
email: achill at matrix dot gatewaynet dot com
mantzios at softlab dot ece dot ntua dot gr

---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster

[Bruce Momjian]

Sure, send the patches to the patches list and we will get them applied.
I am not sure if I can get them into 7.4. It depends if the dbmirror
author can review them.

---------------------------------------------------------------------------

Achilleus Mantzios wrote:

I made a modification on DBMirror.pl,
an addition in the slavedatabase.conf file,
and added another replication table "specialtables".

The goal was to have a way of controlling
when a row of table (if the table is present in specialtables),
will be mirrored to the remote slave.

Lets assume, we have a bank's central IT DEPT master DB
and some branches abroad.

Rows in some tables (e.g. personel, branches, statistics on transactions,
etc...)
have no reason to be replicated to all sites, but only
those sites that these rows refer to:

E.G.
we have
test=# \d personel
Table "public.personel"
Column | Type | Modifiers
---------------+------------------------+-----------
id | integer | not null
name | character varying(20) |
branchid | integer |
test=#

or
test=# \d branch
Table "public.personel"
Column | Type | Modifiers
---------------+------------------------+-----------
id | integer | not null
country | character varying(20) |
address | text |
test=#

And we require that insert, updates on table branch with id = 1
go only to remote site (the ip of) branch 1,
and that inserts,updates on personel with branchid = 2,
in the same fashion, go only to (the ip of) branch 2.

I retain the table specialtables
test=# \d specialtables
Table "public.specialtables"
Column | Type | Modifiers
---------------+------------------------+-----------
tblname | character varying(100) | not null
siteidkeyname | character varying(20) |
Indexes: specialtables_pkey primary key btree (tblname)

test=#

in which for each conditional table, the corresponding
column name (the value of siteidkeyname) is given
which indicates against which column in the PendingData.Data
column is to be examined for equality against the site id.

The site id for each slave is defined in an additional field
in slaveInfo struct in slavedatabase.conf.

Please tell me if i should send the patches
to DBMirror.pl, MirrorSetup.sql, and slavedatabase.conf.

--
================================================== ================
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
Nikis 4, Glyfada
Athens 16610
Greece
tel: [phone]
fax: [phone]
email: achill at matrix dot gatewaynet dot com
mantzios at softlab dot ece dot ntua dot gr

---------------------------(end of broadcast)---------------------------
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--
Bruce Momjian | http://candle.pha.pa.us
pg***@candle.pha.pa.us | [phone]
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073

---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

[Achilleus Mantzios]

Hi,

any news on applying the patches to dbmirror??

Thanx.
On Sun, 10 Aug 2003, Bruce Momjian wrote:

Sure, send the patches to the patches list and we will get them applied.
I am not sure if I can get them into 7.4. It depends if the dbmirror
author can review them.

---------------------------------------------------------------------------

Achilleus Mantzios wrote:

I made a modification on DBMirror.pl,
an addition in the slavedatabase.conf file,
and added another replication table "specialtables".

The goal was to have a way of controlling
when a row of table (if the table is present in specialtables),
will be mirrored to the remote slave.

Lets assume, we have a bank's central IT DEPT master DB
and some branches abroad.

Rows in some tables (e.g. personel, branches, statistics on transactions,
etc...)
have no reason to be replicated to all sites, but only
those sites that these rows refer to:

E.G.
we have
test=# \d personel
Table "public.personel"
Column | Type | Modifiers
---------------+------------------------+-----------
id | integer | not null
name | character varying(20) |
branchid | integer |
test=#

or
test=# \d branch
Table "public.personel"
Column | Type | Modifiers
---------------+------------------------+-----------
id | integer | not null
country | character varying(20) |
address | text |
test=#

And we require that insert, updates on table branch with id = 1
go only to remote site (the ip of) branch 1,
and that inserts,updates on personel with branchid = 2,
in the same fashion, go only to (the ip of) branch 2.

I retain the table specialtables
test=# \d specialtables
Table "public.specialtables"
Column | Type | Modifiers
---------------+------------------------+-----------
tblname | character varying(100) | not null
siteidkeyname | character varying(20) |
Indexes: specialtables_pkey primary key btree (tblname)

test=#

in which for each conditional table, the corresponding
column name (the value of siteidkeyname) is given
which indicates against which column in the PendingData.Data
column is to be examined for equality against the site id.

The site id for each slave is defined in an additional field
in slaveInfo struct in slavedatabase.conf.

Please tell me if i should send the patches
to DBMirror.pl, MirrorSetup.sql, and slavedatabase.conf.

--
================================================== ================
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
Nikis 4, Glyfada
Athens 16610
Greece
tel: [phone]
fax: [phone]
email: achill at matrix dot gatewaynet dot com
mantzios at softlab dot ece dot ntua dot gr

---------------------------(end of broadcast)---------------------------
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subscribe-nomail command to ma*******@postgresql.org so that your
message can get through to the mailing list cleanly

--
================================================== ================
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
Nikis 4, Glyfada
Athens 16610
Greece
tel: [phone]
fax: [phone]
email: achill at matrix dot gatewaynet dot com
mantzios at softlab dot ece dot ntua dot gr
---------------------------(end of broadcast)---------------------------
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