ISAM limits
The following are the capacities and minimum/maximum limits of Synergy ISAM.
Maximum |
Minimum |
|
---|---|---|
Keys defined per file |
255 |
1 |
Segments defined per key |
8 |
1 |
Length of key |
254 on Windows and UNIX (or, 251 if the key allows duplicates or 250 if the key allows duplicates and this is a terabyte file) 255 on OpenVMS |
1 |
Length of key segment |
Same as defined key length |
— |
Number of records per file |
Approximately 250,000,000 for nonterabyte files The actual value varies depending on key size, index density, and available disk space. |
0 |
Record length a |
On Windows and UNIX, use this formula: 65,534 – (3 * number of keys allowing duplicates), – 2 if variable or compressed, – 6 if static RFA, – 2 if static RFA and variable or compressed 32,234 on OpenVMS |
4 |
Size per disk file (.ism and .is1) |
231 (or 248 for terabyte files) |
— |
Combined null key size per file |
1K |
0 |
Keys per duplicate key value |
16,777,216 (or 4 billion for terabyte files) |
— |
Index depth per key |
16 |
— |
Static RFA reuse |
127 |
— |