Purpose
Dieser Report erzeugt Optimizerstatistiken für den qRFC um Problemen desDatenbankoptimizers bei Datenbankzugriffen vorzubeugen.
Bei den qRFC-Tabellen handelt es sich um volatile Tabellen, d.h. dieseTabellen enthalten nicht immer, sondern nur zeitweise Daten. Wenn nunmit den üblichen Hilfsmitteln, wie z.B. Transaktion DB13 oder dem ToolBRCONNECT Statistiken zu einem Zeitpunkt erzeugt werden an dem die qRFCTabellen leer sind, dann treten gehäuft Performanceprobleme auf.

Prerequisites
This report is currently released for Oracle databases only. OutboundqRFC requires a valid RFC destination released for new qRFC. You cancreate this destination in transaction SM59.
All units are mapped to queues with the prefix SAP_DB_STATISTIC_.

Features
The report generates statistics for inbound qRFC, outbound qRFC, and theno-send scenario, as required.
It adds units to the relevant tables, and prevents the queues involvedfrom being executed. It then generates the optimizer statistics.
Once the statistics have been generated, the table DBSTATC is modifiedto prevent a newer version of the statistics from being created for thesame tables. This lock only applies to those utilities that analyze thetable DBSTATC (transaction DB13 and the BRCONNECT tool).
Finally, the units are deleted again.
If the report terminates for some reason (such as a system crash), thegenerated units can be deleted from the monitor. These are unitsgenerated with the queue prefix SAP_DB_STATISTIC_ and the destinationspecified by the user.
Even if the units were executed, this would not cause databaseinconsistencies, since only the empty function module RFC_PING isexecuted in these units.
You can run the report as often as you want, with different numbers ofunits; the last run always overwrites the statistics of earlier runs.
You can also use this report to generate customer-specific statistics.If you set the number of units to 0, only one set of statistics isgenerated. The statistics are created using the data that exists in therelevant tables at this moment in time. However, we recommend that youdo this only if there are enough units in the tables.
You can make a modification in transaction DB21 to remove the tablelocks again.

Selection
The number of units specifies how many units are generated in the tablesbefore the statistics are generated. The following applies:
The more units are generated, the more likely it is that the optimizerwill select the correct indexes. However, more time will be needed togenerate and delete the units and generate the statistics. A goodestimate is about 30 to 60 seconds for 1000 units.
If you want to generate statistics for outbound qRFC, the outboundconnection must be a valid connection from transaction SM59.
You can generate statistics separately for outbound qRFC (server is in adifferent system), inbound qRFC (server is in the same system), and theno-send scenario (units are fetched by a program).

Output
You are notified of any errors. Errors can occur if administrationrights are missing, if a non-compatible database is used, if no outboundconnection has been created (or the connection is not released for newqRFC), or if the statistics cannot be created in the database.