dynamic partitioning

Started by dafNi zafalmost 13 years ago7 messagesgeneral
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#1dafNi zaf
dzaf88@gmail.com

Hello!

I want to dynamically create partition tables that inherit a main table
called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want 5
partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' || from_value
|| 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' || to_value
|| 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole, postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

Attachments:

partitioning_fake_data.sqlapplication/octet-stream; name=partitioning_fake_data.sqlDownload
#2dafNi zaf
dzaf88@gmail.com
In reply to: dafNi zaf (#1)
Re: dynamic partitioning

one note: I create a table of 100 entries in order to test it so I want 5
partition of 20 entries each.
(And not a table of 100000 entries)

thanks again!
dafni

On Wed, Jun 26, 2013 at 4:47 PM, dafNi zaf <dzaf88@gmail.com> wrote:

Show quoted text

Hello!

I want to dynamically create partition tables that inherit a main table
called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want 5
partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' ||
from_value || 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole, postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

#3Daniel Cristian Cruz
danielcristian@gmail.com
In reply to: dafNi zaf (#2)
Re: dynamic partitioning

You forgot to set the trigger on foo:

CREATE TRIGGER foo_insert
BEFORE INSERT ON foo
FOR EACH ROW EXECUTE PROCEDURE foo_insert_trigger();

2013/6/26 dafNi zaf <dzaf88@gmail.com>

one note: I create a table of 100 entries in order to test it so I want 5
partition of 20 entries each.
(And not a table of 100000 entries)

thanks again!
dafni

On Wed, Jun 26, 2013 at 4:47 PM, dafNi zaf <dzaf88@gmail.com> wrote:

Hello!

I want to dynamically create partition tables that inherit a main table
called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want 5
partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' ||
from_value || 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole, postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

#4AI Rumman
rummandba@gmail.com
In reply to: Daniel Cristian Cruz (#3)
Re: dynamic partitioning

Yes, you missed the trigger part. And also you will get error like below
during insert:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_100_to_119)
NOTICE: CREATE TABLE foo_100_to_119 (CHECK ( foo_id >= 100 AND foo_id <=
119 )) INHERITS (foo)
ERROR: new row for relation "foo_100_to_119" violates check constraint
"foo_100_to_119_foo_id_check"
DETAIL: Failing row contains (99, 109, 109, 99, 2013-06-26
16:38:58.466-04).
CONTEXT: SQL statement "INSERT INTO foo_100_to_119 VALUES (($1).*)"
PL/pgSQL function foo_insert_trigger() line 22 at EXECUTE statement

That because you added "entity_id + 1" in your function and hence when you
are giving foo_id = 99, it is creating table with check constraint where
foo_id >= 100 and foo_id <= 119.

I modified it as below:
*from_value = entry_id ;*
*
*
Now its working:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_99_to_119)
NOTICE: CREATE TABLE foo_99_to_119 (CHECK ( foo_id >= 99 AND foo_id <= 119
)) INHERITS (foo)
INSERT 0 0
postgres=# select * from foo;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# select * from foo_99_to_119;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# show constraint_exclusion ;
constraint_exclusion
----------------------
partition
(1 row)

On Wed, Jun 26, 2013 at 10:25 AM, Daniel Cristian Cruz <
danielcristian@gmail.com> wrote:

Show quoted text

You forgot to set the trigger on foo:

CREATE TRIGGER foo_insert
BEFORE INSERT ON foo
FOR EACH ROW EXECUTE PROCEDURE foo_insert_trigger();

2013/6/26 dafNi zaf <dzaf88@gmail.com>

one note: I create a table of 100 entries in order to test it so I want 5
partition of 20 entries each.
(And not a table of 100000 entries)

thanks again!
dafni

On Wed, Jun 26, 2013 at 4:47 PM, dafNi zaf <dzaf88@gmail.com> wrote:

Hello!

I want to dynamically create partition tables that inherit a main table
called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want 5
partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' ||
from_value || 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole, postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

#5dafNi zaf
dzaf88@gmail.com
In reply to: AI Rumman (#4)
Re: dynamic partitioning

I solved the problem with the error! thank you very much!

But there is still 1 issue:

when I insert multiple rows (for exaple with the attachment in my fist
email)
it creates 100 partition tables that contain 1 entry instead of 5
partitions with
20 entries..

Any ideas in that??

Thanks again!

Dafni

On Wed, Jun 26, 2013 at 5:32 PM, AI Rumman <rummandba@gmail.com> wrote:

Show quoted text

Yes, you missed the trigger part. And also you will get error like below
during insert:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_100_to_119)
NOTICE: CREATE TABLE foo_100_to_119 (CHECK ( foo_id >= 100 AND foo_id <=
119 )) INHERITS (foo)
ERROR: new row for relation "foo_100_to_119" violates check constraint
"foo_100_to_119_foo_id_check"
DETAIL: Failing row contains (99, 109, 109, 99, 2013-06-26
16:38:58.466-04).
CONTEXT: SQL statement "INSERT INTO foo_100_to_119 VALUES (($1).*)"
PL/pgSQL function foo_insert_trigger() line 22 at EXECUTE statement

That because you added "entity_id + 1" in your function and hence when you
are giving foo_id = 99, it is creating table with check constraint where
foo_id >= 100 and foo_id <= 119.

I modified it as below:
*from_value = entry_id ;*
*
*
Now its working:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_99_to_119)
NOTICE: CREATE TABLE foo_99_to_119 (CHECK ( foo_id >= 99 AND foo_id <=
119 )) INHERITS (foo)
INSERT 0 0
postgres=# select * from foo;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# select * from foo_99_to_119;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# show constraint_exclusion ;
constraint_exclusion
----------------------
partition
(1 row)

On Wed, Jun 26, 2013 at 10:25 AM, Daniel Cristian Cruz <
danielcristian@gmail.com> wrote:

You forgot to set the trigger on foo:

CREATE TRIGGER foo_insert
BEFORE INSERT ON foo
FOR EACH ROW EXECUTE PROCEDURE foo_insert_trigger();

2013/6/26 dafNi zaf <dzaf88@gmail.com>

one note: I create a table of 100 entries in order to test it so I want
5 partition of 20 entries each.
(And not a table of 100000 entries)

thanks again!
dafni

On Wed, Jun 26, 2013 at 4:47 PM, dafNi zaf <dzaf88@gmail.com> wrote:

Hello!

I want to dynamically create partition tables that inherit a main table
called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want 5
partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' ||
from_value || 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole,
postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

#6AI Rumman
rummandba@gmail.com
In reply to: dafNi zaf (#5)
Re: dynamic partitioning

That because you are generating table name from from_value which is
distinct everytime.
Like,

INSERT INTO foo VALUES (1, 11, 11, 1, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_1_to_21)
NOTICE: CREATE TABLE foo_1_to_21 (CHECK ( foo_id >= 1 AND foo_id <= 21 ))
INHERITS (foo)
INSERT 0 0
postgres=# \d
List of relations
Schema | Name | Type | Owner
--------+---------------+-------+----------
public | foo | table | postgres
public | foo_1_to_21 | table | postgres
public | foo_99_to_119 | table | postgres
(3 rows)

postgres=# INSERT INTO foo VALUES (2, 12, 12, 2, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_2_to_22)
NOTICE: CREATE TABLE foo_2_to_22 (CHECK ( foo_id >= 2 AND foo_id <= 22 ))
INHERITS (foo)
INSERT 0 0
postgres=# \d
List of relations
Schema | Name | Type | Owner
--------+---------------+-------+----------
public | foo | table | postgres
public | foo_1_to_21 | table | postgres
public | foo_2_to_22 | table | postgres
public | foo_99_to_119 | table | postgres
(4 rows)

Here, for two inserts it creates two tables one for foo_id = 1 and other
for foo_id = 2.

Use,
from_value = entry_id/20::int

On Wed, Jun 26, 2013 at 10:50 AM, dafNi zaf <dzaf88@gmail.com> wrote:

Show quoted text

I solved the problem with the error! thank you very much!

But there is still 1 issue:

when I insert multiple rows (for exaple with the attachment in my fist
email)
it creates 100 partition tables that contain 1 entry instead of 5
partitions with
20 entries..

Any ideas in that??

Thanks again!

Dafni

On Wed, Jun 26, 2013 at 5:32 PM, AI Rumman <rummandba@gmail.com> wrote:

Yes, you missed the trigger part. And also you will get error like below
during insert:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_100_to_119)
NOTICE: CREATE TABLE foo_100_to_119 (CHECK ( foo_id >= 100 AND foo_id <=
119 )) INHERITS (foo)
ERROR: new row for relation "foo_100_to_119" violates check constraint
"foo_100_to_119_foo_id_check"
DETAIL: Failing row contains (99, 109, 109, 99, 2013-06-26
16:38:58.466-04).
CONTEXT: SQL statement "INSERT INTO foo_100_to_119 VALUES (($1).*)"
PL/pgSQL function foo_insert_trigger() line 22 at EXECUTE statement

That because you added "entity_id + 1" in your function and hence when
you are giving foo_id = 99, it is creating table with check constraint
where foo_id >= 100 and foo_id <= 119.

I modified it as below:
*from_value = entry_id ;*
*
*
Now its working:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_99_to_119)
NOTICE: CREATE TABLE foo_99_to_119 (CHECK ( foo_id >= 99 AND foo_id <=
119 )) INHERITS (foo)
INSERT 0 0
postgres=# select * from foo;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# select * from foo_99_to_119;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# show constraint_exclusion ;
constraint_exclusion
----------------------
partition
(1 row)

On Wed, Jun 26, 2013 at 10:25 AM, Daniel Cristian Cruz <
danielcristian@gmail.com> wrote:

You forgot to set the trigger on foo:

CREATE TRIGGER foo_insert
BEFORE INSERT ON foo
FOR EACH ROW EXECUTE PROCEDURE foo_insert_trigger();

2013/6/26 dafNi zaf <dzaf88@gmail.com>

one note: I create a table of 100 entries in order to test it so I want
5 partition of 20 entries each.
(And not a table of 100000 entries)

thanks again!
dafni

On Wed, Jun 26, 2013 at 4:47 PM, dafNi zaf <dzaf88@gmail.com> wrote:

Hello!

I want to dynamically create partition tables that inherit a main
table called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want
5 partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' ||
from_value || 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_'
|| to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole,
postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

#7dafNi zaf
dzaf88@gmail.com
In reply to: AI Rumman (#6)
Re: dynamic partitioning

hello again!

since there was a problem with my email and the reply
was not sent, so I'm re-posting my reply..

Again.. the structure as I exported it from phpPgAdmin is:

*-- My table 'foo'
*
*CREATE TABLE foo (
*
* foo_id integer NOT NULL,*
* blaa_id integer NOT NULL,*
* blaa_num integer NOT NULL,*
* foo_num integer NOT NULL,*
* createdatetime timestamp with time zone DEFAULT now()*
*);*

*-- the trigger before insert on table 'foo'
*
*CREATE TRIGGER foo_insert BEFORE INSERT ON foo FOR EACH ROW EXECUTE
PROCEDURE foo_insert_trigger();
*
*
*
*-- The function that is supposed to create dynamically new partition tables
*
*CREATE FUNCTION foo_insert_trigger() RETURNS trigger*
* LANGUAGE plpgsql*
* AS $_$DECLARE*
* entry_id integer;*
* from_value integer;*
* to_value integer;*
* table_name varchar;*
*BEGIN*
* entry_id = NEW.foo_id/20::int;*
* from_value = entry_id;*
* to_value = entry_id + 20;*
* table_name='foo_' || from_value || '_to_' || to_value; *
*
*
* IF not exists(select * from pg_class where relname = table_name) THEN*
* EXECUTE 'CREATE TABLE ' || table_name || ' (CHECK ( foo_id >= ' ||
from_value || ' AND foo_id <= ' || to_value || ' )) INHERITS (foo)' ;*
* EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_' ||
to_value || ' ON ' || table_name || ' USING btree (foo_id, blaa_id,
blaa_num)';*
* EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' || to_value
|| ' ON ' || table_name ||' USING btree (foo_id, foo_num)';*
*
*
* END IF;*
*
*
* EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;*
*
*
* RETURN NULL;*
*END;$_$;*

I insert 100 entries (look into the attached file) so I am expecting
to have 5 partition tables, each of one contains 20 entries:
foo_1_to_20
foo_21_to_40
foo_41_to_60
foo_61_to_80
foo_81_to_100

I did what you suggested: "entry_id = NEW.foo_id/20::int;"
and I solved the problem with the creation of 100 partition
tables containing 1 value

but still there is an error after the insertion of the 21st value:

*partitioning_fake_data.sql:41: ERROR: new row for relation "foo_1_to_21"
violates check constraint "foo_1_to_21_foo_id_check"
CONTEXT: SQL statement "INSERT INTO foo_1_to_21 VALUES (($1).*)"
PL/pgSQL function "foo_insert_trigger" line 19 at EXECUTE statement*
*
*
And also the tables that are created until the error occures are:
foo_0_to_20
foo_1_to_21

Thank you in advance!!

dafni

On Wed, Jun 26, 2013 at 5:55 PM, AI Rumman <rummandba@gmail.com> wrote:

Show quoted text

That because you are generating table name from from_value which is
distinct everytime.
Like,

INSERT INTO foo VALUES (1, 11, 11, 1, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_1_to_21)
NOTICE: CREATE TABLE foo_1_to_21 (CHECK ( foo_id >= 1 AND foo_id <= 21 ))
INHERITS (foo)
INSERT 0 0
postgres=# \d
List of relations
Schema | Name | Type | Owner
--------+---------------+-------+----------
public | foo | table | postgres
public | foo_1_to_21 | table | postgres
public | foo_99_to_119 | table | postgres
(3 rows)

postgres=# INSERT INTO foo VALUES (2, 12, 12, 2, '2013-06-26
16:38:58.466');
NOTICE: table_name = (foo_2_to_22)
NOTICE: CREATE TABLE foo_2_to_22 (CHECK ( foo_id >= 2 AND foo_id <= 22 ))
INHERITS (foo)
INSERT 0 0
postgres=# \d
List of relations
Schema | Name | Type | Owner
--------+---------------+-------+----------
public | foo | table | postgres
public | foo_1_to_21 | table | postgres
public | foo_2_to_22 | table | postgres
public | foo_99_to_119 | table | postgres
(4 rows)

Here, for two inserts it creates two tables one for foo_id = 1 and other
for foo_id = 2.

Use,
from_value = entry_id/20::int

On Wed, Jun 26, 2013 at 10:50 AM, dafNi zaf <dzaf88@gmail.com> wrote:

I solved the problem with the error! thank you very much!

But there is still 1 issue:

when I insert multiple rows (for exaple with the attachment in my fist
email)
it creates 100 partition tables that contain 1 entry instead of 5
partitions with
20 entries..

Any ideas in that??

Thanks again!

Dafni

On Wed, Jun 26, 2013 at 5:32 PM, AI Rumman <rummandba@gmail.com> wrote:

Yes, you missed the trigger part. And also you will get error like below
during insert:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_100_to_119)
NOTICE: CREATE TABLE foo_100_to_119 (CHECK ( foo_id >= 100 AND foo_id
<= 119 )) INHERITS (foo)
ERROR: new row for relation "foo_100_to_119" violates check constraint
"foo_100_to_119_foo_id_check"
DETAIL: Failing row contains (99, 109, 109, 99, 2013-06-26
16:38:58.466-04).
CONTEXT: SQL statement "INSERT INTO foo_100_to_119 VALUES (($1).*)"
PL/pgSQL function foo_insert_trigger() line 22 at EXECUTE statement

That because you added "entity_id + 1" in your function and hence when
you are giving foo_id = 99, it is creating table with check constraint
where foo_id >= 100 and foo_id <= 119.

I modified it as below:
*from_value = entry_id ;*
*
*
Now its working:

INSERT INTO foo VALUES (99, 109, 109, 99, '2013-06-26 16:38:58.466');
NOTICE: table_name = (foo_99_to_119)
NOTICE: CREATE TABLE foo_99_to_119 (CHECK ( foo_id >= 99 AND foo_id <=
119 )) INHERITS (foo)
INSERT 0 0
postgres=# select * from foo;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# select * from foo_99_to_119;
foo_id | blaa_id | blaa_num | foo_num | createdatetime
--------+---------+----------+---------+----------------------------
99 | 109 | 109 | 99 | 2013-06-26 16:38:58.466-04
(1 row)

postgres=# show constraint_exclusion ;
constraint_exclusion
----------------------
partition
(1 row)

On Wed, Jun 26, 2013 at 10:25 AM, Daniel Cristian Cruz <
danielcristian@gmail.com> wrote:

You forgot to set the trigger on foo:

CREATE TRIGGER foo_insert
BEFORE INSERT ON foo
FOR EACH ROW EXECUTE PROCEDURE foo_insert_trigger();

2013/6/26 dafNi zaf <dzaf88@gmail.com>

one note: I create a table of 100 entries in order to test it so I
want 5 partition of 20 entries each.
(And not a table of 100000 entries)

thanks again!
dafni

On Wed, Jun 26, 2013 at 4:47 PM, dafNi zaf <dzaf88@gmail.com> wrote:

Hello!

I want to dynamically create partition tables that inherit a main
table called "foo".
The creation must occur when needed.

For example, lets say that I want to insert 100000 entries and I want
5 partition
tables (with 20000 entries each).

So, first I need a partition for the first 20000 entries and when the
entries reach
the number 20000, another partition must be created, e.t.c..

I guess I need something like that:

--the main table is:

CREATE TABLE foo (
foo_id integer NOT NULL,
blaa_id integer NOT NULL,
blaa_num integer NOT NULL,
foo_num integer NOT NULL,
createdatetime timestamp with time zone DEFAULT now()
);

--and the trigger function is:

CREATE OR REPLACE FUNCTION foo_insert_trigger()
RETURNS trigger AS $$
DECLARE
entry_id integer;
from_value integer;
to_value integer;
table_name varchar;
BEGIN
entry_id = NEW.foo_id;
from_value = entry_id + 1;
to_value = entry_id + 20;
table_name='foo_' || from_value || '_to_' || to_value;

IF not exists(select * from pg_class where relname = table_name) THEN
EXECUTE 'CREATE TABLE ' || table_name || '(CHECK ( foo_id >=' ||
from_value || 'AND foo_id <=' || to_value || ' )) INHERITS (foo)' ;
EXECUTE 'CREATE UNIQUE INDEX by_blaa_num_' || from_value || '_to_'
|| to_value || 'k ON ' || table_name ||' USING btree (foo_id, blaa_id,
blaa_num)';
EXECUTE 'CREATE UNIQUE INDEX pk_foo_' || from_value || '_to_' ||
to_value || 'k ON ' || table_name ||' USING btree (foo_id, foo_num)';
EXECUTE 'GRANT ALL ON TABLE ' || table_name || ' TO foorole,
postgres';
EXECUTE 'GRANT SELECT ON TABLE ' || table_name || ' TO blarole';

END IF;

EXECUTE 'INSERT INTO ' || table_name ||' VALUES (($1).*)' USING NEW ;

RETURN NULL;
END;
$$
LANGUAGE plpgsql;

but it doesn't seem to work. It doesn't actually create new partition
tables.
The entries are inserted into "foo"

I attach a test .sql file that contains the data of the table

any help would save me from a lot of time!

thank you in advance!

dafni

--
Daniel Cristian Cruz
クルズ クリスチアン ダニエル

Attachments:

partitioning_fake_data.sqlapplication/octet-stream; name=partitioning_fake_data.sqlDownload