CacheData File Size
- Last Updated: May 12, 2026
- 1 minute read
- OpenAccess SDK
- Version 9.0
- Documentation
To estimate the CacheData file size, you need to know the overhead of storing records on disk. Use the following overhead factors when estimating the total size:
- Overhead per record: 2 bytes, if record size is less than 65536 bytes. 6 bytes for larger size record.
- Overhead per column: 3 to 6 bytes depending upon column type and total columns in the record.
The following table shows the overhead for each column in a record.
Overhead for Each Column in a Record
| Data Type | Less than 255 Total Columns in Record/td> | More than 255 Total Columns in Record/td> |
| CHAR(254) | 3 bytes | 5 bytes |
| DATE | 3 bytes | 5 bytes |
| DOUBLE | 3 bytes | 5 bytes |
| FLOAT | 3 bytes | 5 bytes |
| INTEGER | 3 bytes | 5 bytes |
| LONGVARBINARY | 6 bytes | 8 bytes |
| NUMERIC | 3 bytes | 5 bytes |
| REAL | 3 bytes | 5 bytes |
| SMALLINT | 3 bytes | 5 bytes |
| TIME | 3 bytes | 5 bytes |
| TIMESTAMP | 3 bytes | 5 bytes |
| VARCHAR | 4 bytes | 6 bytes |
Example 1
If the record has 5 CHAR fields, each with a width of 20 bytes, then the record area size is 117 bytes (2 + 5 * (3 + 20)).
The space overhead for 5 fields is 17%. This means 3.4% space overhead per field.
Example 2
If the record has 5 INTEGER fields, then the record area size is 37 bytes (2 + 5 * (3 + 4)).
The space overhead for 5 fields is 85%. This means 17% space overhead per field.