Foglight for Oracle (Cartridge) 5.9.3.20 - User Guide

Object Name

The name of the invalid object

Object Type

The type of the invalid object

PDB

In multitenant architectures, the name of the pluggable database.

Schema Name

The name of the schema that contains the invalid objects

Realtime Collection

20

Online

60

Offline

300

Avg Read Time

The average time (ms) spent reading a data block from the disk into the database buffer cache. 

Avg Write Time

The average time spent (ms) writing a data block from the database buffer to the disk.

Balance Average Read Time

The extent, in percents, to which average read time is balanced across RAC nodes

Balance Average Write Time

The extent, in percents, to which average write time is balanced across RAC nodes

Balance Cache Hit Ratio

The extent, in percents, to which cache hit ratio is balanced across RAC nodes

Balance Logical Reads

The extent, in percents, to which logical reads are balanced across RAC nodes

Balance Physical Reads

The extent, in percents, to which physical reads are balanced across RAC nodes

Balance Physical Writes

The extent, in percents, to which physical writes are balanced across RAC nodes

Block Changes per Call

This ratio measures the amount of data manipulation within existing database tables, which each transaction performs via DML commands, by computing the average number of blocks changed per single user call. Bea cu se creating or dropping indexes modifies index blocks, such operations increment the value of this metric.

Block Reads

This rate determines the block get rate, which is a basic measure of the rate at which the application system references the database. Change in metric size may indicate that the database workload has materially increased or that the referenced segment sizes increased.

Cache Hit Ratio

The effectiveness of the buffer cache, computed by comparing the number of block requests, which found the block in the buffer cache, with the entire block requests (including requests that required disk reads).

Chained Row Ratio

This ratio measures the percentage of chained or migrated rows encountered during a fetch as a percentage of the entire fetched rows.

Consistent Changes

The number of times a user process has applied rollback entries to perform a consistent read on the block.

Consistent Gets

The number of data block reads in CONSISTENT mode (that is, consistent reads). A CONSISTENT read retrieves the block version as of the time the query started.

Consistent Gets Direct

The number of times a consistent read was carried out directly for a block, bypassing the buffer cache.

Consistent Gets From Cache

The number of times a consistent read was carried out for a block from buffer cache.

DB Block Changes

The number of database blocks in memory (SGA) that were modified by the session as a result of DML activity. Such changes generate redo log entries, thereby becoming permanent changes to the database if the transaction is committed.

DB Block Gets

The number of data block reads in CURRENT mode (that is, current reads). A CURRENT read retrieves the latest version of the block as of the time of reading. Current mode reads are usually associated with DML activity.

DB Block Gets Direct

Number of times a CURRENT block was retrieved directly, bypassing the buffer cache.

DB Block Gets From Cache

Number of times a CURRENT block was retrieved from the buffer cache.

Disk Sorts Ratio

The number of sort operations that require creation of temporary segments on disk to store the intermediate sort results. This occurs if the data being sorted cannot be fit into memory block specified by the SORT_AREA_SIZE parameter in the init.ora file.

Full Scan Ratio

This ratio measures the percentage of the rows, which were retrieved as a result of full table scans, within the total number of retrieved rows.

Oracle Data I/O Operations

Total number of I/O operations  (both physical and logical) performed by the Oracle session.

Oracle Physical Data Processed

the total size (in megabytes) of data processed via physical read and write operations during the specified time range.

Oracle Physical I/O Operations

Total number of physical I/O operations performed by the Oracle session.

Physical Read Bytes

The number of data blocks read by Oracle, which are not present in the buffer cache or in the PGA, thereby requiring I/O read operations, that is: the total number of data blocks read from disk.

Physical Read IO Requests

Number of read requests for application activity (mainly buffer cache and direct load operation) that read one or more database blocks per request.

Physical Read Total Bytes

Total size in bytes of disk reads by all database instance activity, including application reads, backup and recovery, and other utilities. The difference between this value and the value of the metric physical read bytes provides the total read size in bytes by non-application workload.

Physical Read Total IO Requests

Number of read requests that read one or more database blocks for all instance activity including application, backup and recovery, and other utilities. The difference between this value and the value of the metric physical read total multi block requests provides the total number of single block read requests.

Physical Read Total Multi Block Requests

Total number of read requests which read in two or more database blocks per request for all instance activity including application, backup and recovery, and other utilities.

Physical Reads

The number of data blocks read by Oracle, which are not present in the buffer cache or in the PGA, thereby requiring I/O read operations, that is: the total number of data blocks read from disk.

Physical Reads Cache

Total number of data blocks read from disk into the buffer cache.

Physical Reads Direct

Number of reads that were carried out directly from disk into the PGA, bypassing the buffer cache.

Physical Reads Refetch Warmup

Number of data blocks that were read from the disk during the automatic pre-warming of the buffer cache.

Physical Write Bytes

Total size, in bytes, of all disk writes from the database application activity (this metric does not include any other kind of instance activity).

Physical Write IO Requests

Number of write requests for application activity (mainly buffer cache and direct load operation) that wrote one or more database blocks per request.

Physical Write Total Bytes

Total size, in bytes, of all disk writes for the database instance, including application activity, backup and recovery, and other utilities. The difference between this value and the value of the metric physical write bytes provides the total write size, in bytes, resulting from non-application workload.

Physical Write Total IO Requests

Number of write requests which wrote one or more database blocks from all instance activity including application activity, backup and recovery, and other utilities. The difference between this metric value and the value of the metric physical write total multi block requests provides the number of single block write requests.

Physical Write Total Multi Block Requests

Total number of Oracle instance write requests that wrote two or more blocks per request to the disk for all instance activity, including application activity, recovery and backup, and other utilities.

Physical Writes

Total number of data blocks written to disk. This metric represents the rate at which Oracle generates system I/O calls.

Physical Writes Direct

Number of writes directly to disk, bypassing the buffer cache

Physical Writes From Cache

Total number of data blocks written to disk from the buffer cache

Physical Writes Non Checkpoint

Number of times a buffer is written for reasons other than checkpoint. This statistic measures the number of writes that would have occurred had no checkpoint operation taken place. Subtracting this value from the value of the metric physical writes provides the number of I/O operations carried out as a result of checkpoint operations.

Read Consistency Overhead

This ratio measures the extent to which applications must make use of the read consistency mechanism. The queries that processing parts of the UPDATE and/or DELETE operations are subject to read consistency.

Read Time

The total time spent on reading data from the data file.

Reads Per Second

Number of physical reads carried out per second

Redo Blocks Written

Total number of redo blocks written. Dividing this metric by the value of the metric redo writes provides the average number of blocks per write.

Redo Buffer Allocation Retries

Total number of retries necessary to allocate space in the redo buffer. Retries are needed either because the redo writer has fallen behind or because an event such as a log switch is occurring.

Redo Entries

The number of redo records created (copied into the redo log buffer).

Redo Log Space Requests

Number of times the active log file is full and the session must wait for a log switch to be performed. After the completion of the log switch, the redo log entries can be allocated, and the session can be resumed.

Redo Log Space Wait Ratio

Redo Size

Total size, in bytes, of the redo volume.

Redo Writes

Total number of write operations issued by LGWR to the redo log files.

Session Logical Reads

The number of data blocks read by Oracle, which are already present in the buffer cache, thereby requiring no I/O read operations. The value of this metric is a summary of the db block gets and consistent gets metrics.

Sorts (Disk)

Sorts (disk) are sorts that require creation of temporary segments on disk to store the intermediate sort results. Such sorts are carried out if the data being sorted cannot be fit into memory block specified by the SORT_AREA_SIZE parameter in the init.ora file.

Sorts (Memory)

Number of sort operations that were carried out entirely in memory, without requiring any disk writes. The sort operation can take place in memory if the sorted data can be fit into the memory block specified by the SORT_AREA_SIZE parameter in the init.ora file.

Sorts (Rows)

The total number of rows sorted.

Table Scan Blocks Gotten

The number of blocks encountered during the full table scans

Table Scan Short Tables

The number of times Oracle carried out a complete scan of a short table

Table Scans Cache Partitions

Number of range scans performed on tables that have the CACHE option enabled

Table Scans Direct Read

Number of table scans performed using direct read (bypassing the buffer cache)

Table Scans Fetch by ROWID

Number of rows that were fetched using a ROWID (usually recovered from an index)

Table Scans Long Tables

The number of times Oracle carried out a complete scan of a long table

Table Scans ROWID Ranges

The number of table scans conducted during parallel query by the query slaves, with the specified ROWID ranges

Table Scans Rows Gotten

The number of rows scanned during full table scans. High values may indicate use of non-optimal queries, absence of proper indexing, or both.

Tables Fetch Continued Row

Number of times a chained or migrated row is encountered during a fetch.

Total Physical Data I/O Operations

The total number of read and write operations carried out for the data file.

Total Sorts

Total number of sort operations, including both in-memory and disk sorts.

User Calls

Number of user calls such as login, parse, fetch, or execute. The value of this metric represents the rate at which the user application addresses Oracle.

User Commits

Number of transactions committed during the current interval. After a transaction is committed, the redo generated by that transaction reflects the changes made to database blocks, and the database blocks must be written to disk.

User Rollbacks

Number of transactions that were rolled back, either because of an error or as a result of a manually executed ROLLBACK command

Write Time

The total time spent on writing data to the datafile

Writes Per Second

The number of times DBWR was required to write per second.

Realtime Collection

60

Online

60

Offline

300

Active Jobs

The number of currently running jobs

Jobs Idle

The number of scheduled jobs that are currently not running

Jobs Waiting

The number of jobs that are scheduled to be running now but waiting in queue for the resources

Total Jobs

The total number of scheduled jobs

Realtime Collection

20

Online

60

Offline

300

Cache Buffer Chain Latch

This latch is acquired whenever a block in the buffer cache is accessed (pinned)

Cache Buffer LRU Chain Latch

This latch is acquired in order to introduce a new block into the buffer cache and when writing a buffer back to disk, specifically when trying to scan the LRU chain that contains all of the dirty blocks in the buffer cache

Latch Free Waits

Number of waits for a latch that is currently busy (held by another process)

Library Cache Latch

This latch is acquired in order to add a new statement to the library cache. During a parse, Oracle searches the library cache for a matching statement. If one is not found, then Oracle will parse the SQL statement, obtain the library cache latch and insert the new SQL.

Library Cache Pin Latch

This latch is acquired when a statement in the library cache is re-executed

Redo Allocation Latch

This latch is acquired in order to allocate space within the redo log buffer. There is one redo allocation latch per instance.

Redo Copy Latch

This latch is acquired in order to write redo records into the redo log buffer. There may be up to LOG_SIMULTANEOUS_COPIES allocation latches.

Shared Pool Latch

This Latch is acquired when allocating and freeing memory in the shared pool

Total Active Time

Total amount of time waited for the event (in seconds)