1.0

ranges). The columns must also be of the same type, not considering constraints. Any REDUNDANCY or BUCKETS
clause must also be the same as the tables with which it is colocated.
Note: In order for two partitioned tables to be colocated, the SERVER GROUPS clauses in both CREATE
TABLE statements must be identical. In order for two replicated tables to be colocated, both tables must
specify the same server groups or one table's server groups must be a subset of the other table's server
groups.
For example, if you create the partitioned table, "countries," as follows:
CREATE TABLE COUNTRIES
(
COUNTRY VARCHAR(26) NOT NULL CONSTRAINT COUNTRIES_UNQ_NM Unique,
COUNTRY_ISO_CODE CHAR(2) NOT NULL CONSTRAINT COUNTRIES_PK PRIMARY KEY,
REGION VARCHAR(26),
CONSTRAINT COUNTRIES_UC
CHECK (country_ISO_code = upper(country_ISO_code) )
) PARTITION BY PRIMARY KEY
You can colocate another table, "cities," using the command:
CREATE TABLE CITIES
(
CITY_ID INTEGER NOT NULL CONSTRAINT CITIES_PK Primary key,
CITY_NAME VARCHAR(24) NOT NULL,
COUNTRY VARCHAR(26) NOT NULL,
AIRPORT VARCHAR(3),
LANGUAGE VARCHAR(16),
COUNTRY_ISO_CODE CHAR(2) CONSTRAINT COUNTRIES_FK
REFERENCES COUNTRIES (COUNTRY_ISO_CODE)
) PARTITION BY COLUMN (COUNTRY_ISO_CODE)
COLOCATE WITH (COUNTRIES)
In this example, both "countries" and "cities" are partitioned using the COUNTRY_ISO_CODE column. Rows
with the same COUNTRY_ISO_CODE value are colocated on the same SQLFire members.
See the CREATE TABLE reference page for more information.
Making a Partitioned Table Highly Available
Use the REDUNDANCY clause to specify a number of redundant copies of a table for each partition to maintain.
Because SQLFire is primarily a memory-based data management system, it is important to use redundancy when
necessary to enable fail-over if a member shuts down or fails. However, keep in mind that maintaining a large
number of redundant copies has an adverse impact on performance, network usage, and memory usage. A
REDUNDANCY value of 1 is recommended to maintain a secondary copy of the table data. For example:
CREATE TABLE COUNTRIES
(
COUNTRY VARCHAR(26) NOT NULL,
COUNTRY_ISO_CODE CHAR(2) NOT PRIMARY KEY,
REGION VARCHAR(26),
)
REDUNDANCY 1
SQLFire attempts to place copies of the same bucket onto hosts that have different IP addresses if possible, to
protect against machine failure. However, if there is only one machine available SQLFire places multiple copies
on that machine. Setting the enforce-unique-host boot property prevents SQLFire from ever placing
multiple copies on the same machine.
vFabric SQLFire User's Guide58
Managing Your Data in vFabric SQLFire