onstat -C command: Print B-tree scanner information
Use the -C command to display information about the B-tree scanner subsystem and each B-tree scanner thread.
Syntax: >>-onstat-- -C--+-prof--+-------------------------------------->< +-hot---+ +-part--+ +-clean-+ +-range-+ +-map---+ +-alice-+ '-all---'
The following options are available with the onstat
-C command and can be combined:
- prof
- Prints the profile information for the system and each B-tree scanner thread. This is the default option.
- hot
- Prints the hot list index key in the order to be cleaned
- part
- Prints all partitions with index statistics
- clean
- Prints information about all the partitions that were cleaned or need to be cleaned
- range
- Prints the savings in pages processed by using index range scanning
- map
- Displays the current bitmaps for each index being cleaned by the alice cleaning method
- alice
- Displays the efficiency of the alice cleaning method option
- all
- Prints all onstat -C options
Example output using the prof option
Figure 1. onstat -C command
output with the prof option
Btree Cleaner Info
BT scanner profile Information
==============================
Active Threads 1
Global Commands 2000000 Building hot list
Number of partition scans 11003
Main Block 0xc000000003c9dc68
BTC Admin 0xc0000000024bc208
BTS info id Prio Partnum Key Cmd
0xc000000003c9dee8 0 High 0x00000000 0 40 Yield N
Number of leaves pages scanned 77
Number of leaves with deleted items 6
Time spent cleaning (sec) 0
Number of index compresses 0
Number of deleted items 113
Number of index range scans 0
Number of index leaf scans 0
Number of index alice scans 2 Output description using the prof option
- Id
- BTSCANNER ID
- Prio
- Current priority of BTSCANNER
- Partnum
- The partition number for the index this thread is currently working on
- Cmd
- Command this thread is processing currently
Example output using the hot option
Figure 2. onstat -C command
output with the hot option
Btree Cleaner Info
Index Hot List
==============
Current Item 5 List Created 15:29:47
List Size 4 List expires in 0 sec
Hit Threshold 500 Range Scan Threshold -1
Partnum Key Hits
0x00100191 1 14 *
0x00A00022 1 13 *
0x00100191 2 8 *
0x00100150 2 7 * Output description using the hot option
- Partnum
- The partition number for an index
- Key
- Index Key
- Hits
- The current value of the Hit counter
- *
- Indicates that this partition has been cleaned during this hot list duration
Example output using the part option
Figure 3. onstat -C command
output with the part option
Btree Cleaner Info
Index Statistics
================
Partnum Key Positions Compress Split
0x00100002 1 146 0 0
0x00100004 1 4 0 0
0x00100004 2 13 0 0
0x00100005 1 1 0 0
0x00100005 2 0 0 0
0x00100006 1 1 0 0
0x00100006 2 0 0 0
0x00100007 2 1 0 0
0x00100008 2 1 0 0
0x0010000a 1 0 0 0
0x0010000e 3 1 0 0
0x00100011 1 1 0 0
0x00100013 2 2 0 0 Output description using the part option
- Partnum
- The partition number for an index
- Key
- Index Key
- Positions
- Number of times index has been read
- Compress
- Number of pages which have been compressed
- Split
- Number of splits that have occurred
- C
- Indicates partition is busy being cleaned
- N
- Index partition no longer eligible for cleaning
Example output using the clean option
Figure 4. onstat -C command
output with the clean option
Btree Cleaner Info
Index Cleaned Statistics
=========================
Partnum Key Dirty Hits Clean Time Pg Examined Items Del Pages/Sec
0x00100013 2 2 0 0 0 0.00
0x0010008b 3 1 0 0 0 0.00
0x001000c7 1 2 0 0 0 0.00
0x00100150 2 7 0 0 0 0.00
0x0010016f 2 2 0 0 0 0.00
0x00100191 1 14 0 0 0 0.00
0x00100191 2 8 0 0 0 0.00
0x00a00011 2 6 0 0 0 0.00
0x00a00013 1 0 0 24 0 24.00
0x00a00019 1 0 0 470 225 470.00
0x00a00022 1 13 0 0 0 0.00
0x00a00022 2 5 0 0 0 0.00 Output description using the clean option
- Partnum
- The partition number for an index
- Key
- Index Key
- Dirty Hits
- Number of times a dirty page has been scanned
- Clean Time
- Total time spent, in seconds
- Pg Examined
- Number of pages examined by btscanner thread
- Items Del
- Number of items removed form this index
- Pages/Sec
- Number of pages examined per second
- C
- Indicates partition is busy being cleaned
- N
- index partition is no longer eligible for cleaning
Example Output
Figure 5. onstat -C range
Btree Cleaner Info
Cleaning Range Statistics
=========================
Partnum Key Low High Size Saving
0x001001bc 2 36 69 96 65.6 %
0x001001be 1 16 20 48 91.7 %
0x001001cd 1 8 21 32 59.4 %
0x001001cd 2 24 25 32 96.9 %
Output Description
- Partnum
- The partition number
- Key
- Index Key
- Low
- Low boundary for range scan
- High
- High boundary for index scan
- Size
- Size of index in pages
- Saving
- Percentage of time saved versus a full scan
- C
- Indicates partition is busy being cleaned
- N
- Index partition is no longer eligible for cleaning
Example Output
Figure 6. onstat -C map
Btree Cleaner Info
ALICE Bitmap of Deleted Index Items
===================================
Partnum Key Map
0x00100013 2 0000: 80000000 00000000
0x0010008b 3 0000: 80000000 00000000
0x001000c7 1 0000: 80000000 00000000
0x00100150 2 0000: 80000000 00000000
0x0010016f 2 0000: 80000000 00000000
0x00100191 1 0000: 80000000 00000000
0x00100191 2 0000: 80000000 00000000
0x00a00011 2 0000: 80000000 00000000
0x00a00013 1 0000: 00000000 00000000
0x00a00019 1 0000: 00000000 00000000
0x00a00022 1 0000: 80000000 00000000
0x00a00022 2 0000: 80000000 00000000Output Description
- Partnum
- The partition number
- Key
- Index Key
- Map
- Alice bitmap
Example Output
Figure 7. onstat -C alice
Btree Cleaner Info
ALICE Cleaning Statistics
=========================
System ALICE Info: Mode = 6, Eff = 30 %, Adj = 5
Partnum Mode BM_Sz Used_Pg Examined Dirty_Pg # I/O Found Eff Adj
0x00100013 6 64 97 0 0 0 0 0.0 % 0
0x0010008b 6 64 5 0 0 0 0 0.0 % 0
0x001000c7 6 64 2 0 0 0 0 0.0 % 0
0x00100150 6 64 91 0 0 0 0 0.0 % 0
0x0010016f 6 64 91 0 0 0 0 0.0 % 0
0x00100191 6 64 26 0 0 0 0 0.0 % 0
0x00100191 6 64 26 0 0 0 0 0.0 % 0
0x001001bc 0 0 91 0 0 0 0 0.0 % 0
0x001001cd 0 0 26 0 0 0 0 0.0 % 0
0x001001cd 0 0 26 0 0 0 0 0.0 % 0
0x00a00011 6 64 91 0 0 0 0 0.0 % 0
0x00a00013 6 64 25 24 3 3 1 33.3 % 1
0x00a00019 6 64 470 470 3 3 2 66.7 % 1
0x00a00022 6 64 26 0 0 0 0 0.0 % 0
0x00a00022 6 64 26 0 0 0 0 0.0 % 0
Output Description
- Partnum
- The partition number for an index
- Mode
- The alice mode for the current partition
- BM_Sz
- The size allocated for the bitmap
- Used_Pg
- The size of the index in pages (used)
- Dirty_Pg
- Number of dirty pages
- # I/O
- Number of pages read
- Found
- Number of dirty pages found in reads
- Eff
- How efficient was the bitmap
- Adj
- Number of times the alice efficiency level for the partition was insufficient and was adjusted