The following table lists various sizes, capacities and limits for ISAM-A files and processing. Note, however, that some of these limits have been arbitrarily set just for efficiency. If you have legitimate need for larger limits, contact us. Also note that where the word "extension" appears in the table below, this indicates a feature that was not present in the AMOS version and which may require some modification to your application; see A-Shell Extensions for more details.
|
Feature |
Specification |
|
Maximum record size |
8192 |
|
Maximum number of keys per record |
20 |
|
Maximum DAT file size |
Prior to A-Shell 4.9.948: 2GB As of A-Shell 4.9.948: 1TB |
|
Maximum IDX file size |
Prior to A-Shell 5.1.1134: 2GB As of A-Shell 5.1.1134: 1TB |
|
Maximum # of records per file |
2 ^ 31 |
|
Maximum bytes per key |
80 |
|
Maximum parts (fields) per key |
20 |
|
Maximum number of duplicate keys |
65536 |
|
Compressed keys |
yes (optional, extension) |
|
Compressed data records |
yes (optional, extension) |
|
Transaction support |
yes (extension) |
|
File recovery from log |
yes (extension) |
|
Audit trail |
maybe (extension, under consideration) |
|
Auto expansion of file |
yes |
|
Index rebuild utility |
yes |
|
Index verification utility |
yes |
|
Add/delete index without dump/reload |
yes |
|
ODBC / OLEDB / SQL access |
yes (via third party utilities) |
|
Maximum INPUT CSV line length |
4k |
|
Maximum ? TAB(x) |
4095 in A-Shell 5.1, 472 in A-Shell 5.0 |