AWR Key Metrics

I/O Section: This section shows the all important I/O activity for the instance and shows I/O activity by tablespace, data file, and includes buffer pool statistics.

1. Tablespace IO Stats

2. File IO Stats

3. Buffer Pool Statistics

Advisory Section: This section show details of the advisories for the buffer, shared pool, PGA and Java pool.

1. Buffer Pool Advisory

2. PGA Aggr Summary: PGA Aggr Target Stats; PGA Aggr Target Histogram; and PGA Memory Advisory.

3. Shared Pool Advisory

4. Java Pool Advisory

Buffer Wait Statistics: This important section shows buffer cache waits statistics.

Enqueue Activity: This important section shows how enqueue operates in the database. Enqueues are special internal structures which provide concurrent access to various database resources.

Undo Segment Summary: This section gives a summary about how undo segments are used by the database.

Undo Segment Stats: This section shows detailed history information about undo segment activity.

Latch Activity: This section shows details about latch statistics. Latches are a lightweight serialization mechanism that is used to single-thread access to internal Oracle structures.

1. Latch Sleep Breakdown

2. Latch Miss Sources

3. Parent Latch Statistics

4. Child Latch Statistics

Segment Section

This report section provides details about hot segments using the following criteria:

  • Logical Reads: Includes top segments which experienced high number of logical reads.
  • Physical Reads: Includes top segments which experienced high number of disk physical reads.
  • Buffer Busy Waits: These segments have the largest number of buffer waits caused by their data blocks.
  • Row Lock Waits: Includes segments that had a large number of row locks on their data.
  • ITL Waits: Includes segments that had a large contention for Interested Transaction List (ITL). The contention for ITL can be reduced by increasing INITRANS storage parameter of the table.

Dictionary Cache Stats: This section exposes details about how the data dictionary cache is operating.

Library Cache Activity: Includes library cache statistics describing how shared library objects are managed by Oracle.

SGA Memory Summary: This section provides summary information about various SGA regions.

init.ora Parameters: This section shows the original init.ora parameters for the instance during the snapshot period.

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