Document Type | Technical Information
Category | Tuning
Applicable Product Versions | 6FS04, 6FS05, 6FS06, 6FS07, 6FS07PS, 7FS01, 7FS02, 7FS02PS
Document Number | TTUTI005
Overview
This document provides the meanings of each column stored in the backup table when backing up statistics information in Tibero DB.
Method
When backing up statistics information periodically, it is necessary to accurately understand the meanings of each column in the backup table to check and analyze the statistics information at a specific point in time.
- Create Statistics Table
EXEC DBMS_STATS.CREATE_STAT_TABLE(OWNNAME => 'user_name', STATTAB => 'statistics_table_name')
- Backup Statistics Information
EXEC DBMS_STATS.EXPORT_SCHEMA_STATS(OWNNAME => 'user_name', STATTAB => 'statistics_table_name');
Assuming the backup was done as above, the meanings of the statistics table columns are as follows.
Explanation of Key Columns in Statistics Table
- Table Column Information
Column Name | Meaning |
|---|---|
C1 | table name (Table Name) |
C4 | partition name (Partition Name) |
N1 | row_cnt (Number of Rows) |
N2 | blk_cnt (Number of Blocks) |
N3 | avg_rln (Average Row Length) |
- Index Column Information
Column Name | Meaning |
|---|---|
C1 | index name (Index Name) |
C4 | partition name (Partition Name) |
N1 | row_cnt (Number of Rows) |
N2 | blk_cnt (Number of Blocks) |
N3 | distinct_key (Distinct Key) |
N4 | leaf_blk_cnt (Number of Leaf Blocks) |
N5 | blevel (B-tree b-level) |
N6 | clufac (Clustering Factor) |
- Individual Column Information
Column Name | Meaning |
|---|---|
C1 | table name (Table Name) |
C4 | column name (Column Name) |
N1 | null_cnt (Number of Nulls) |
N2 | sample_size (Sample Size) |
N3 | distinct_cnt (Number of Distinct Keys) |
N4 | density (Density) |
N5 | avg_col_size (Average Column Size) |
CL1 | low_val (Minimum Value) |
CH1 | high_val (Maximum |
- Histogram Bucket Column Information
Column Name | Meaning |
|---|---|
N6 | bucket_no (Bucket Number) |
N7 | distinct_cnt (Number of Unique Values in Bucket) |
CH2 | end_point_actual (End Point Value) |
- Common Column Information
Column Name | Meaning |
|---|---|
C5 | owner name (Object Owner Name) |
D1 | analyze_time (Analysis Time) |