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admin:features:grids:creation:sql [2011/01/11 02:38] els |
admin:features:grids:creation:sql [2012/10/26 15:00] (current) |
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| === 2. Partition the database === | === 2. Partition the database === | ||
| - | If the database will be logically partitioned, then create the relational views that correlate with the partitioning strategy. If the database will be physically partitioned using an Omnidex Snapshot, then partition the database using the PARTITION command. | + | If the database will be logically partitioned, then create the relational views that correlate with the partitioning strategy. If the database will be physically partitioned using an Omnidex Snapshot, then partition the database using the PARTITION statement. |
| - | The PARTITION command is available in the Omnidex SQL language, and is callable from the OdxSQL application. Since the command is in the Omnidex SQL language, it may also be called directly from ODBC and JDBC. | + | The PARTITION statement is available in the Omnidex SQL language, and is callable from the OdxSQL application. Since the statement is part of the Omnidex SQL language, it may also be called directly from ODBC and JDBC. |
| - | The PARTITION command allows the table to be partitioned one of three ways, 1) into a specific number of equally sized partitions, 2) into separate partitions based on a partition qualifier consisting of a column or a SQL expression, or 3) a combination of these two steps. In the third case, Omnidex will evaluate the cardinality of the partition qualifier and group values together to comprise the specific number of partitions in as equal size as possible. The syntax of the PARTITION command is: | + | The PARTITION statement allows the table to be partitioned one of three ways, 1) into a specific number of equally sized partitions, 2) into separate partitions based on a partition qualifier consisting of a column or a SQL expression, or 3) a combination of these two steps. In the third case, Omnidex will evaluate the cardinality of the partition qualifier and group values together to comprise the specific number of partitions in as equal size as possible. The syntax of the PARTITION statement is: |
| PARTITION table [INTO n [PARTITIONS]] [BY column] | PARTITION table [INTO n [PARTITIONS]] [BY column] | ||
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| [WITH options] | [WITH options] | ||
| - | An example of a command to partition a table is: | + | An example of a statement to partition a table is: |
| PARTITION LIST BY “STATE || SUBSTRING(ZIP from 1 for 2)” | PARTITION LIST BY “STATE || SUBSTRING(ZIP from 1 for 2)” | ||
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| Here is an example of a CREATE ENVIRONMENT statement for an Omnidex Grid. | Here is an example of a CREATE ENVIRONMENT statement for an Omnidex Grid. | ||
| - | <code> | + | <code sql> |
| create environment "list_env" | create environment "list_env" | ||
| maxthreads 4 | maxthreads 4 | ||
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| == The CREATE DATABASE statement == | == The CREATE DATABASE statement == | ||
| - | The CREATE DATABASE statement is used to declare the database characteristics for each node. The NODE declarations in the CREATE DATABASE statement are show below. Consult the documentation on the [[admin:environments:create:sql:syntax#create_database | CREATE DATABASE]] statement for the complete syntax. | + | The CREATE DATABASE statement is used to declare the database characteristics for each node. The NODE declarations in the CREATE DATABASE statement are show below. Consult the documentation on the [[dev:sql:statements:create_database:home | CREATE DATABASE]] statement for the complete syntax. |
| <code> | <code> | ||
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| Here is an example of a CREATE DATABASE statement for an Omnidex Grid. | Here is an example of a CREATE DATABASE statement for an Omnidex Grid. | ||
| - | <code> | + | <code sql> |
| create database "list" | create database "list" | ||
| node NODE01 | node NODE01 | ||
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| == The CREATE TABLE statement == | == The CREATE TABLE statement == | ||
| - | The CREATE TABLE statement is used to declare the table characteristics for each node for each partitioned table in the grid. The NODE declarations in the CREATE TABLE statement are show below. Consult the documentation on the [[admin:environments:create:sql:syntax#create_table | CREATE TABLE]] statement for the complete syntax. | + | The CREATE TABLE statement is used to declare the table characteristics for each node for each partitioned table in the grid. The NODE declarations in the CREATE TABLE statement are show below. Consult the documentation on the [[dev:sql:statements:create_table:home | CREATE TABLE]] statement for the complete syntax. |
| <code> | <code> | ||
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| Here is an example of a CREATE TABLE statements for an Omnidex Grid. | Here is an example of a CREATE TABLE statements for an Omnidex Grid. | ||
| - | <code> | + | <code sql> |
| create table "HOUSEHOLDS" | create table "HOUSEHOLDS" | ||
| node NODE01 | node NODE01 | ||
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| As discussed in the [[admin:features:grids:partitions#how_are_referential_constraints_handled_such_as_primary_and_foreign_keys| partition scheme]], it is necessary to partition tables so that referential integrity is maintained. Typically, the parent is partitioned using criteria, as shown for HOUSEHOLDS above, and the child is partitioned along the foreign key. The PARTITION BY clause for a child shows the join criteria, as shown below: | As discussed in the [[admin:features:grids:partitions#how_are_referential_constraints_handled_such_as_primary_and_foreign_keys| partition scheme]], it is necessary to partition tables so that referential integrity is maintained. Typically, the parent is partitioned using criteria, as shown for HOUSEHOLDS above, and the child is partitioned along the foreign key. The PARTITION BY clause for a child shows the join criteria, as shown below: | ||
| - | <code> | + | <code sql> |
| create table "INDIVIDUALS" | create table "INDIVIDUALS" | ||
| node NODE01 | node NODE01 | ||