Tablespace (KUDTABSPACE) attributes (Superseded)

This attribute group is superseded. There is a new attribute group with the same name that replaces it.

Avg Direct Read Time The time (in milliseconds) for performing the direct reads for the tablespace.

Avg Direct Write Time The time (in milliseconds) for performing the direct writes for the tablespace.

Avg Pool IO Time The average time (in milliseconds) for performing buffer pool input and output operations (reading or writing) for the tablespace. A high average time can indicate the existence of an input and output conflict. In this case, you might need to move data to a different device. The returned value includes the time applied to asynchronous input and output operations (which are performed by prefetchers and page cleaners).

Avg Pool Read Time The average time (in milliseconds) for processing read requests that caused data or index pages to be physically read from disk to buffer pool for the tablespace. A high average time generally indicates the existence of an input and output conflict. In this case, you might need to move data to a different device. The returned value includes the time applied to asynchronous read operations that are performed by prefetchers.

Avg Pool Write Time The average time (in milliseconds) for processing write requests that caused data or index pages to be physically written from buffer pool to disk for the tablespace. A high average time generally indicates the existence of an input and output conflict. In this case, you might need to move data to a different device. The returned value includes the time applied to asynchronous write operations that are performed by page cleaners.

Avg Sect Read The average number of sectors that are read for this tablespace for each direct read. Direct reads do not use the buffer pool, and so result in poor performance because the data is physically read from disk each time. If you are using system monitors to track input and output for the device, this returned value helps you distinguish database input and output from non-database input and output.

Avg Sect Written The average number of sectors that are written for this tablespace for each direct read. Direct writes do not use the buffer pool, and so result in poor performance because the data is physically written from disk each time. If you are using system monitors to track input and output for the device, this returned value helps you distinguish database input and output from non-database input and output.

Avg Sync Data Read Time The average time (in milliseconds) for synchronous data reads for the tablespace. Use the returned value to analyze the input and output work being performed for the tablespace. Synchronous read operations are performed by database manager agents. Asynchronous reads are performed by prefetchers, which read data pages from disk into the buffer pool in anticipation of their use.

Avg Sync Data Write Time The average time (in milliseconds) for synchronous data writes for the tablespace. Use the returned value to analyze the input and output work being performed for the tablespace. Synchronous write operations are performed by database manager agents. Asynchronous writes are performed by page cleaners, which write out changed pages to disk and free up space in the buffer pool.

Avg Sync IO Time The average time (in milliseconds) for synchronous input and output operations for the tablespace. Use the returned value to analyze the input and output work being performed for the tablespace. Synchronous input and output operations are performed by database manager agents. Asynchronous input and output operations are performed by prefetchers (reads) and page cleaners (writes). In general, asynchronous input and output helps your applications run faster.

Container Name Indicates the location of the container. Value format is a simple text string with a maximum of 32 characters.

Container Name (Unicode) Indicates the location of the container (Unicode). Value format is a simple text string with a maximum of 768 characters.

DB Name Represents the real name of the database for which information is collected or to which the application is connected. This name was given to the database when it was created. Value format is a simple text string with a maximum of 32 characters.

DB Name (Unicode) Represents the real name of the database for which information is collected or to which the application is connected (Unicode). This name was given to the database when it was created. Value format is a simple text string with a maximum of 96 characters.

Direct Read Reqs The number of requests to perform a direct read from disk of one or more sectors of data for the database. The returned value is used in calculating the returned value for the average number of sectors read per direct read for the tablespace. Direct reads are performed in units, the smallest being a 512-byte sector. They are used while the system is doing any of the following operations: reading LONG VARCHAR columns, reading LOB columns, or performing a backup.

Direct Read Time The time (in milliseconds) for performing the direct reads for the tablespace since the first connection. The returned value is used in calculations for the average direct read time (ms). A high average time can indicate an input and output conflict.

Direct Reads The number of requests to perform a direct read from disk of one or more sectors of data for the tablespace since the first connection.

Direct Write Reqs The number of requests to perform a direct write to disk of one or more sectors of data for the database. The returned value is used in calculating the returned value for the average number of sectors written per direct write. Direct writes are performed in units, the smallest being a 512-byte sector. They are used while the system is doing any of the following operations: writing LONG VARCHAR columns, writing LOB columns, performing a restore, or performing a load.

Direct Write Time The time (in milliseconds) for performing the direct writes for the tablespace since the first connection. The returned value is used in calculations for the average direct write time (ms). A high average time can indicate an input and output conflict.

Direct Writes The number of direct writes to disk for the tablespace since the first connection. The returned value is used in calculating the returned value for the average number of sectors written per direct write. Direct writes are performed in units, the smallest being a 512-byte sector. They are used while the system is doing any of the following operations: writing LONG VARCHAR columns, writing LOB columns, performing a restore, or performing a load.

Estore RW Ratio The ratio (as a percentage) of pages (data plus index) copied from extended storage to pages copied to extended storage within the tablespace. When a page is transferred from extended storage to the buffer pool, you save a system input and output call. However, you still incur the cost of attaching to the extended memory segment, copying the page, and detaching from the segment. Use the returned value to determine if you would benefit from using extended storage. The higher the ratio, the more likely you are to benefit. In general, extended storage is particularly useful if input and output activity is very high on your system.

Extent Size Indicates the extent size. A valid value is an integer.

Files Closed The total number of closed files for the tablespace since the first database connection.

Free Pages Represents the number of free pages associated with the database. A valid value is an integer.

Instance Name (Unicode) The name of the monitored DB2 instance (Unicode). The valid format is a text string with a maximum of 60 bytes.

Node Name For new installations of version 6, release 2, the format is instanceid:hostname:UD for all operating systems. The format for version 6, release 1 of the DB2 agent on Windows systems is instanceid:hostname:UD; on UNIX and Linux® systems, the format is instanceid:hostname.

Num Containers Indicates the number of containers used. A valid value is an integer.

Object ID Represents the identifier for the object. A valid value is an integer.

Page Size Indicates the page size. A valid value is an integer.

Pending Free Pages Represents the number of pending free pages associated with the database. A valid value is an integer.

Pool Async Data Read Reqs The number of asynchronous data read requests.

Pool Async Data Reads The number of data pages read asynchronously into the buffer pool for the tablespace. Compare the returned value with number of synchronous reads to gain insight into how well the prefetchers are working.

Pool Async Data Writes The number of times a buffer pool data page was physically written asynchronously to disk for the tablespace. Compare the returned value with the number of synchronous writes to gain insight into how well the page cleaners are working.

Pool Async Index Read Reqs The number of asynchronous index read requests.

Pool Async Index Reads The number of index pages read asynchronously into the buffer pool by a prefetcher within the tablespace. By comparing the ratio of asynchronous to synchronous reads, you can determine how well the prefetchers are working. Asynchronous reads are performed by database manager prefetchers.

Pool Async Index Writes The number of times a buffer pool index page was written asynchronously to disk for the tablespace. Subtract the returned value from the buffer pool index writes to calculate the number of synchronous index writes. By comparing the number of asynchronous index writes to synchronous index writes, you can gain insight into how well the buffer pool page cleaners are performing. This ratio can be helpful when you are refining the num_iocleaners configuration parameter.

Pool Async Read Time The total time (in milliseconds) that database manager prefetchers spent reading data into the buffer pool for the tablespace. Compare the returned value to the synchronous read time to understand where input and output time is being spent.

Pool Async Write Time The total time (in milliseconds) that database manager page cleaners spent writing data or index pages from the buffer pool to disk for the tablespace. Compare the returned value to the synchronous write time to understand where input and output time is being spent.

Pool Data from Estore The number of buffer pool data pages copied from extended storage within the tablespace to the buffer pool. Required pages are copied from extended storage to the buffer pool if they are not in the buffer pool but are in extended storage. This copying can incur the cost of connecting to the shared memory segment but saves the cost of a disk read.

Pool Data L Reads The number of logical read requests for data pages that went through the buffer pool for the tablespace since the connection occurred. The returned value includes requests for data that is already in the buffer pool or read from disk into the buffer pool to fulfill the request.

Pool Data P Reads The number of read requests requiring input and output to get data pages into the buffer pool for the tablespace since the first connection.

Pool Data Reads The number of read requests to get data pages into the buffer pool for the tablespace.

Pool Data to Estore The number of buffer pool data pages copied to extended storage for the tablespace.

Pool Data Writes The number of times that a buffer pool data page was physically written to disk for the tablespace.

Pool Hit Pct The percent buffer pool hit ratio (data plus index).

Pool Hit Ratio for Interval The overall buffer pool hit ratio (as a percentage) for the database during the monitoring interval. This hit ratio includes both index and data page activity. The overall buffer pool hit ratio indicates the percentage of page requests for which the database manager did not need to load a page from disk to service. (That is, the page was already in the buffer pool.) The greater the buffer pool hit ratio, the lower the frequency of disk input and output. If the hit ratio is low compared to normal operating levels, increasing the number of buffer pool pages can improve performance. A ratio of zero indicates that pages needed to be read for every request. For a large database, increasing the buffer pool size can have a minimal effect on the buffer pool hit ratio. Such a database can have so large a number of data pages that the statistical chance of a hit is not increased by an increase of the buffer pools. However, even though the data might be too large to fit in the buffer pool, the entire index can fit. In this case, you can refine buffer pool sizes until the overall buffer pool hit ratio stops increasing, and then refine the buffer pool until the buffer pool index hit ratio no longer increases.

Pool Index Hit Pct for Interval The percent buffer pool index hit ratio for the monitoring interval.

Pool Index from Estore The number of buffer pool index pages copied from extended storage for the tablespace.

Pool Index L Reads The number of logical read requests for index pages that went through the buffer pool for the tablespace since the connection. The returned value includes requests for index pages that are already in the buffer pool or read from disk into the buffer pool to fulfill the request.

Pool Index P Reads The number of physical read requests to get index pages into the buffer pool for the tablespace.

Pool Index to Estore The number of buffer pool index pages copied to extended storage within the tablespace. Pages are copied from the buffer pool to extended storage when they are selected as victim pages. This copying is required to make space for new pages in the buffer pool.

Pool Index Writes The number of times that a buffer pool index page was physically written to disk for the tablespace since the first connection. If the returned value is high compared to the buffer pool index physical reads, you can improve performance by increasing the available buffer pool space.

Pool IO per Sec The rate (per second) for buffer pool input and output for the tablespace. Buffer pool input and output includes all physical data and index pages that go through the buffer pool when read or written.

Pool Read Time The time (in milliseconds) spent reading data from the buffer pool to disk for the tablespace since the first connection.

Pool Sync Data Reads The number of buffer pool synchronous data reads.

Pool Sync Data Writes The number of buffer pool synchronous data writes.

Pool Sync Index Reads The number of buffer pool synchronous index reads.

Pool Sync Index Writes The number of buffer pool synchronous index writes.

Pool Write Time The time (in milliseconds) spent writing data from the buffer pool to disk for the tablespace since the first connection.

Prefetch Pct for Interval The percentage of asynchronous read requests that were satisfied for a tablespace during the last monitoring interval.

Prefetch Reqs for Interval The number of prefetch requests for the tablespace during the monitoring interval.

Prefetch Size Indicates the prefetch size. A valid value is an integer.

Space Used DMS Table Pct The percentage of space used in the Database Managed Space (DMS) tablespace. Use the returned value to determine if the tablespace needs more space.

Sync Read Time The time (in milliseconds) applied to synchronous reads for the tablespace. Compare the returned value to the buffer pool async read time to understand where input and output time for this tablespace is used.

Sync Write Time The time (in milliseconds) spent synchronously writing data to disk from the buffer pool for the tablespace. Compare the returned value to the value returned by the buffer pool async write time attribute to understand where input and output time for this tablespace is used.

Tablespace ID Represents the identifier for the tablespace. A valid value is an integer.

Tablespace Name Represents the tablespace name of DB2. Value format is a simple text string with a maximum of 32 characters.

Tablespace Name (Unicode) Represents the tablespace name of DB2 (Unicode). Value format is a simple text string with a maximum of 768 bytes.

Tablespace Status The status of the tablespace. DB2 sets this value, which corresponds to the DB2 tablespace_state element in the DB2 tablespace_nodeinfo Snapshot logical data group. This element contains a hexadecimal value that indicates the current tablespace state. The externally visible state of a tablespace is composed of the hexadecimal sum of certain state values. For example, if the state is quiesced: EXCLUSIVE and Load pending, the value is 0x0004 + 0x0008, which is 0x000c.

Total Direct IO Time The total time (in milliseconds) for direct reads to and writes from the tablespace.

Total IO Pct The percentage total of I/O.

Total Pages Represents the number of total pages available associated with the database. A valid value is an integer.

Total Pool IO Time The total pool I/O time.

Total Pool P Read Time The time (in milliseconds) spent reading data and index pages from the buffer pool to the disk for the tablespace since the first connection. The value format is an integer. This attribute is the same as the pool read time attribute.

Total Pool P Write Time The total pool physical write time.

Total Sync IO The total number of synchronous reads and writes for both data and index pages for the tablespace.

Total Sync IO Time The total time (in milliseconds) for processing requests for synchronous reads or writes within the tablespace.

Usable Pages Represents the number of usable pages associated with the database. A valid value is an integer.

Used Pages Represents the total number of used pages. A valid value is an integer.

Version Indicates the version number of DB2. A valid value is an integer.