Spotlight on Oracle 10.7 - Getting Started Guide

Note: Oracle In-Memory is available for Oracle 12c Release 1 (12.1.0.2) and above. Data is displayed for Oracle instances where In-Memory is available and has been enabled. In-Memory is disabled by default.

Drilldown on the In-Memory segments consuming the most I/O and disk resources. Assess the time saved by having the segment In-Memory and use this information to determine whether it is worth having the segment in memory.

To open the Segments page

Select the Spotlight on Oracle connection in the Spotlight Browser.
Click Configuration & Memory | In-Memory Page | Segments Page.

Top Segments by In-Memory Scans

Show the memory segments of in-memory tables. Show the segments with the most In-Memory scans (Top 100) in descending order of magnitude.

Column

Description

Name

The name of the segment. Invariably this segment will be of type table.

Owner

The owner of the segment.

Populate Status

The status of populating the segment. The status is started, completed or failed.

IM Distribute

Applicable in the case of an Oracle RAC. The DISTRIBUTE clause controls how table data in the In-Memory column store is distributed across Oracle RAC instances.

AUTO	The Oracle Database controls how data is distributed across Oracle RAC instances. Large tables are distributed across Oracle RAC instances depending on their access patterns. Smaller tables may be distributed between instances. If you specify only the DISTRIBUTE keyword or omit the inmemory_distribute clause entirely then AUTO is the default.
BY ROWID RANGE	Data in certain ranges of rowids is distributed to different Oracle RAC instances.
BY PARTITION	Data in partitions is distributed to different Oracle RAC instances.
BY SUBPARTITION	Data in subpartitions is distributed to different Oracle RAC instances.

IM Duplicate

Applicable in the case of an Oracle RAC. The DUPLICATE clause controls how table data in the In-Memory column store is duplicated across Oracle RAC instances.

DUPLICATE	Data is duplicated on one Oracle RAC instance. The data exists on two Oracle RAC instances.
DUPLICATE ALL	Data is duplicated across all Oracle RAC instances. This causes DISTRIBUTE AUTO regardless of any setting specified for the inmemory_distribute clause.
NO DUPLICATE	Data is not duplicated across Oracle RAC instances. This is the default.

IM Compression

NO MEMCOMPRESS	Data is populated without any compression
MEMCOMPRESS FOR DML	Minimal compression optimized for DML performance
MEMCOMPRESS FOR QUERY LOW	Optimized for query performance (default)
MEMCOMPRESS FOR QUERY HIGH	Optimized for query performance as well as space saving
MEMCOMPRESS FOR CAPACITY LOW	Balanced with a greater bias towards space saving
MEMCOMPRESS FOR CAPACITY HIGH	Optimized for space saving

IM Priority

The priority determines the order in which segments are populated in the In-Memory column store.

Critical	The object is populated immediately after the database is opened.
High	The object is populated after all CRITICAL objects have been populated, if space remains available in the In-Memory column store.
Medium	The object is populated after all CRITICAL and HIGH objects have been populated, and space remains available in the In-Memory column store.
Low	The object is populated after all CRITICAL, HIGH, and MEDIUM objects have been populated, if space remains available in the In-Memory column store.
None	The object is populated only after objects with "none" priority are scanned for the first time (Default), if space is available in the In-Memory column store.

Size on Disk (Mbytes)

The size of the segment on disk.

IM Size (Mbytes)

The size of the segment in the In-Memory column store.

Bytes not Populated (Mbytes)

The size of the portion of the on-disk segment that is not populated in memory.

Logical Reads

The number of logical reads on the segment.

DB Block Changes

The number of DB block changes on the segment.

Number of Indexes

The number of indexes in the segment (table).

IM Scans

The number of In-Memory scans on the segment.

Physical Reads

The number of physical reads on the segment. Physical reads are read from disk.

Container Name

The name of the container for the pluggable database.

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Spotlight on Oracle 10.7 - Getting Started Guide

Segments Page