SharePlex requires a tablespace for its internal tables in each database involved in replication. With the exception of the SHAREPLEX_ROWIDMAP and SHAREPLEX_LOBMAP tables, the SharePlex tables use the tablespace's default storage settings
If the tables to be replicated have extensive chaining or LOB columns, take the following into account when sizing the tablespace.
Row chaining considerations:
The size of the SHAREPLEX_ROWIDMAP table increases with the amount of row chaining. For initial installations of SharePlex (installing clean, not as an upgrade*), this table and its indices each have a 5 MB INITIAL extent, 5 MB NEXT extent, and PCTINCREASE of 0. The MAXEXTENTS is unlimited, allowing the table to grow as much as necessary. If you expect a large amount of chaining, you can estimate how big the SHAREPLEX_ROWIDMAP table will be with the following formula: (2.5) x (number of chained rows) x (57 bytes) divided by 1024 = number of kilobytes If the database is using the cost-based Optimizer (CBO), incorporate the SHAREPLEX_ROWIDMAP table into the analysis schedule.
LOB considerations :
The SHAREPLEX_LOBMAP table is created with a 1 MB INITIAL extent, 1 MB NEXT extent, and PCTINCREASE of 10. The MAXEXTENTS of this table is 120,
allowing it to grow to 120 MB. There is one entry in the table for each LOB in the replicating tables. Each entry can be up to 27 bytes. The default storage usually
accommodates this table, permitting more than 4 million LOB entries. If you expect more than that, size the SharePlex tablespace accordingly, taking into account that this table shares the tablespace with the SHAREPLEX_ROWIDMAP and the other SharePlex tables. The SHAREPLEX_LOBMAP table does not contain entries for LOBs stored in-row. If the database is using the cost-based Optimizer (CBO) and the replicating tables include numerous LOBs, incorporate the SHAREPLEX_LOBMAP table into the analysis schedule.
SharePlex requires a temporary tablespace where it can perform sorts and other operations. This tablespace will be used for sorts when the compare commands are used to compare source and target tables to verify synchronization. Compares performed on large tables require large sorting operations, especially if there are no primary or unique keys. If you expect to be using these commands, take into account sorting requirements when sizing the SharePlex temporary tablespace or choosing an existing temporary tablespace for SharePlex.The default tablespace is the tablespace where the SharePlex tables are installed.
SharePlex requires an index tablespace for the indices for its internal tables. The default for this tablespace is the tablespace for the SharePlex tables, but performance will be enhanced if the SharePlex tables and indices are on separate tablespaces to minimize I/O contention. If you have a previous version of SharePlex, the SharePlex indices were installed in the tablespace where you installed the SharePlex tables. These indices are not moved when you install this version of SharePlex, but it is recommended that you move them to the index tablespace you are defining for this installation. If the existing SharePlex indices are on an index tablespace, you can specify that tablespace for this installation.
