Document Type | Technical Information
Category | Monitoring/Inspection
Document Number | TMOTI017
Overview
The Data Block Address is an address combining the data file number and the block number, indicating which block the data block is located in within the data file.
This guide explains how to check the block number and datafile number using the DBA (Data Block Address) value.
Method
When the DBA (Data Block Address) value is 16871262, the datafile number corresponds to the upper 10 bits of the dba value, and the block number corresponds to the lower 22 bits of the dba value.
Below is the method to convert to binary and search for the Datafile number, Block Number, and Object.
1. Convert the DBA number to binary.
- 16871262 โ 1000000010110111101011110
2. Separate into the lower 22 bits and the remaining bits.
- 100 / 0000010110111101011110
- Datafile Number: 100(2) => 4(10)
- Block Number: 0000010110111101011110(2) => 94046(10)
3. Use the values obtained above to search for the Object.
select * from dba_extents where file_id=4 and 94046 between block_id and (block_id + blocks - 1);