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Table Of Contents

Using the Default Disk Store

Tables that do not name a disk store but specify persistence or overﬂow in their CREATE TABLE statement are

automatically assigned to the default disk store, SQLF-DEFAULT-DISKSTORE. Also, gateway,

AsyncEventListener, and DBSynchronizer queues always use the default disk store. The default diskstore is

saved to the SQLFire data store's working directory, unless you change the value of the sys-disk-dir boot

property to specify another location.

Create a Disk Store

You create a named disk store in the data dictionary using the CREATE DISKSTORE DDL statement. You

then assign the disk store to an individual table by specifying the disk store in the table's CREATE TABLE DDL

statement. You can store data from multiple tables and queues in the same named disk store.

Persist Table Data to a Disk Store

You conﬁgure the persistence settings for a partitioned or replicated table when you create the table with the

CREATE TABLE DDL statement. SQLFire automatically recovers data from disk for persistent tables when

you restart SQLFire members.

Procedure

1. Ensure that the data dictionary is persisted in your SQLFire cluster. SQLFire persists the data dictionary by

default for all data stores, but you can explicitly enable or disable data dictionary persistence using the

persist-dd boot property.

Note: All SQLFire data stores in the same cluster must use a consistent persist-dd value. Accessors

cannot persist data, and you cannot set persist-dd to true for an accessor.

2. Create the disk store that you want to use for persisting the table's data, or use the default disk store. See

Creating a Disk Store or Using the Default on page 75.

3. Specify table persistence and the named disk store in the CREATE TABLE statement. For example:

CREATE TABLE Orders(OrderId INT NOT NULL,ItemId INT )

persistent 'OrdersDiskStore' asynchronous

This example uses asynchronous writes to persist table data to the "OrdersDiskStore."

Note: Persistent tables must be associated with a disk store. If you do not specify a named disk store

in the CREATE TABLE statement, SQLFire persists the table to the default disk store. For example,

the following statement persists the new table to the default disk store:

CREATE TABLE Orders(OrderId INT NOT NULL,ItemId INT )

persistent asynchronous

Note: When you specify asynchronous persistence, asynchronous writes to the disk store use certain

disk store attributes. See Disk Store Persistence Attributes on page 71.