SQL/MX 2.x Installation and Management Guide (G06.24+, H06.03+)

Managing an SQL/MX Distributed Database
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Dropping Distributed Objects
Dropping Distributed Objects
Before you can drop a distributed table, index, or view, all objects dependent on that
table and its metadata must be accessible.
For range-partitioned tables or indexes, use the MODIFY utility to drop empty partitions
on remote nodes. For hash-partitioned tables and indexes, use MODIFY to drop
nonempty partitions only.
Enhancing Performance for a Distributed
Database
The performance issues of a distributed database encompass those of a local
database and also include:
•
Effective use of local partitions and indexes
•
Use of replicated data to increase local performance
•
Use of remote servers to increase performance
These issues, not covered in this manual, also affect performance of a distributed
database:
•
Network availability and use
•
Remote node availability
For additional information about enhancing performance, see Section 16, Enhancing
SQLMX Database Performance.
Using Local Partitions and Indexes
Defining local partitions of a table so that the local partition can satisfy a significant
number of local queries can improve performance. Also, the local partition remains
available to satisfy the queries even when other nodes are unavailable.
Performance might also improve for queries on a remote table if a local index exists to
resolve queries locally. If the local index columns can resolve a query, the SQL/MX
executor does not need to query the remote table.
Before defining the index or local partitions, first weigh their benefits against any
performance consequences that occur when the underlying table is modified. Note that
INSERT, UPDATE, or DELETE statements performed on the table from anywhere in
the network require access to the local index and possibly to the local partition.
For an example of creating a local index on a remote table, see Example—Creating a
Remote Table and a Local Index on page 13-20.