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Set the redundancy-zone boot property to ensure that SQLFire places redundant copies on specic zones
that you dene. For example, to ensure that redundant copies are placed on different racks, set the redundancy-zone
for each machine to the logical name of the rack on which the machine runs.
See Boot PropertiesYou specify boot properties when starting a SQLFire server with the FabricServer API; when
you make the rst connection to an embedded SQLFire member with the JDBC embedded driver; and when
you use the sqlf connect peer command. .
Limiting the Memory Consumption on a Member
Use the MAXPARTSIZE clause of the CREATE TABLE statement to load- balance partitioned data among the
available members.
The MAXPARTSIZE Attribute on page 460 clause species the maximum memory for any partition on a SQLFire
member.
Rebalancing Partitioned Data on SQLFire Members
You can use rebalancing to dynamically increase or decrease your SQLFire cluster capacity, or to improve the
balance of data across the distributed system.
Rebalancing is a SQLFire member operation that affects partitioned tables created in the cluster. Rebalancing
performs two tasks:
If the a partitioned table's redundancy setting is not satised, rebalancing does what it can to recover redundancy.
See Making a Partitioned Table Highly Available on page 58.
Rebalancing moves the partitioned table's data buckets between host members as needed to establish the best
balance of data across the distributed system.
For efciency, when starting multiple members, trigger the rebalance a single time, after you have added all
members.
Note: If you have transactions running in your system, be careful in planning your rebalancing operations.
Rebalancing may move data between members, which could cause a running transaction to fail with a
TransactionDataRebalancedException.
Start a rebalance operation using one of the following options:
At the command line when you boot a SQLFire server:
sqlf server start -rebalance
Eexecuting a system procedure in a running SQLFire member:
call sys.rebalance_all_buckets();
This procedure initiates rebalancing of buckets across the entire SQLFire cluster for all partitioned tables.
How Partitioned Table Rebalancing Works
The rebalancing operation runs asynchronously.
As a general rule, rebalancing takes place on one partitioned table at a time. For tables that have colocated data,
rebalancing works on the tables as a group, maintaining the data colocation between the tables.
You can continue to access partitioned tables while rebalancing is in progress. Queries, DML operations, and
procedure executions continue while data is moving. If a procedure executes on a local data set, you may see a
performance degradation if that data moves to another member during procedure execution. Future invocations
are routed to the correct member.
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Partitioning Tables