Partitioned file usage depends on specific file attributes to be present. With c-treeDB and SQL created files, these resources and extended headers are transparent to your application. C-based ISAM applications require these extended header attributes be defined at the application layer.
The file must be created with Xtd8 creation function (extended file header) with ctPARTAUTO in the Xtd8 file mode.
The relative partition index number must be defined in your Xtd8 create block.
XCREblk xcreblk[2] = {0, 0};
xcreblk[0].x8mode |= ctPARTAUTO;
xcreblk[0].prtkey = 0;
To use a DODA field in your partition rule, you must define the index with a SCHSEG mode. Beginning December 16, 2023, all other key segment modes are also recognized.
The partition rule must evaluate to an integer.
Supported FairCom DB Features
Partitioned files support most, but not all, FairCom DB features.
Partitioned files support SQL query across all partitions, with query optimizations for specific range searching.
Partitioned files can be created, accessed and administered via ISAM and c-treeDB, C/C++, .NET, and Java interfaces.
Partitioned files can be included in hot backups.
While not required, HUGE file support is strongly recommended as partitioned data are designed and intended for large volumes of data. However, functions requiring a record offset must use the ctSETHGH() and ctGETHGH() functions, even if the partitioned files are not HUGE to ensure high-order bytes are included.
Transaction Processing is fully supported. When enabled, requires transaction-dependent (TRANDEP) creates which is automatically enforced.
Auto-numbering SRLSEG is managed from the data file host header to maintain serial numbers used by key segments across all partitions.
Two levels of unique keys are supported. Global unique keys across all partitions as well as partition member specific unique keys.
Partitioned files can be encrypted being mindful of prior encryption keys required for any reactivated archived member.
Host file security attributes are propagated to all partitioned file members including file passwords.
Partitioned files can be rebuilt in entirety from the host, or independently at the member level.
