Database writes

No database writes are collected if DBIO=NONE (except for DEDBs).

If DBIO=BFALTERS:

• All writes are collected at the database level.
• Writes to maintain a secondary index or logical database are collected. Counts are maintained at the database level (DBPCB).

If DBIO=I OWAITS:

• Most writes are collected at the transaction level and reported under the database entry ALLDBS , including all writes occurring at sync point (the majority). These counts correspond closely to the DC Monitor IWAITS that are reported under the I/O PCB (Program I/O report).
• Database writes that occur during call processing (such as the deletion of a HISAM root) are accumulated by database.
• Writes to maintain a secondary index or logical database are collected under the DBD that is the actual target (DBPCB).
• VSAM-initiated writes for buffer steal and background write are not measured.
• OSAM buffer steal writes are accumulated in the (otherwise unused) NO I/O counter for the database/transaction whose read request forced the buffer steal.
• Chained VSAM or OSAM writes of multiple buffers count as one write.