This section lists the errors that may be encountered when using the B Tree system. The occurrence of most of these errors indicates a serious failure in the B Tree system, with the following exceptions:
- QNOKEY
The key given as a parameter to
bfndky(or its brethren) does not exist.- QDUP
The key given as a parameter to
binsky(or its brethren) already exists in the index. Duplicate keys are not permitted.- QBUSY
File busy, a normal hazard when using shared access mode in a multiuser environment.
- QNOWRT
The B Tree file was originally opened with read-only permission, and a write has subsequently been attempted. Probably an application program error.
- QNOBTF
Attempt to perform operation on B Tree file, but there is no file attached to the context pointer provided, likely an application error.
- QINERR
Attempt made to open the same file again, likely an application error.
- QDELCR
An attempt has been made to delete the current root, or worse, the super root. This is forbidden by the BT library.
- QBADOP
Unknown debug option passed to bdbug, likely an application error.
- QNOACT
Maximum number of concurrently open B Tree files reached - may be an application error.
- QBADAP
Illegal context pointer passed to a B Tree function - may be an application error.
- QDNEG
A negative length data record has been passed to a B Tree function.
- QBADVR
The B Tree index file was created using an older version of the B Tree library, and cannot be accessed safely with this version. Extract data using a program based on the previous version of the B Tree library, and import into a index file created with the new version.
- QDAOVR
A new data record cannot be entered as the maximum value of a data block pointer has been exceeded.
- QF2BIG
The index file has reached its maximum size for this implementation.
- QBADAL
Unable to set alarm for for file lock handling. This may be a problem with the underlying OS.
Table 4.1. B Tree Error Messages
| 1 | QSRNR | The block at the super root location is not a root |
| 2 | QCLSIO | Unable to close index file: "file" |
| 3 | QCRTIO | Unable to create index file: "file" |
| 4 | QCPBLK | Unable to read source or destination block |
| 5 | QWRBLK | I/O error writing block |
| 6 | QRDSUP | I/O error reading super root |
| 7 | QWRSUP | I/O error writing super root |
| 8 | QOPNIO | I/O error opening index file: "file" |
| 9 | QRDBLK | I/O error reading block |
| 10 | QIXOPN | An index file is already open |
| 11 | QSPLIT | Can't split full block |
| 12 | QINFER | Bad info block index used |
| 13 | QNOMEM | Unable to acquire a free memory block |
| 14 | QSTKUF | Stack underflow |
| 15 | QSTKOF | Stack overflow |
| 16 | QBLKFL | Can't insert key at block |
| 17 | QLOCTB | Replace location out of range |
| 18 | QSPKEY | Split: search for middle key failed |
| 19 | QWRMEM | Requested write block not in memory |
| 20 | QBALSE | Balance: search for key failed |
| 21 | QDELEX | Exact flag not set for delete |
| 22 | QDELER | Internal inconsistency in delete operation |
| 23 | QDELRP | Search for deleted key replacement failed |
| 24 | QDEMSE | Demote search failed |
| 25 | QDEMSP | Demote split failed |
| 26 | QJNSE | Join search failed |
| 27 | QNODEF | Cannot locate default root ($$default) |
| 28 | QDELCR | Deletion of the current or super root is forbidden |
| 29 | QBADIX | Negative in-memory index encountered |
| 30 | QNOBTF | No index file open for this operation |
| 31 | QINERR | Index file already in use |
| 32 | QBADOP | Debug option not recognised |
| 33 | QNOACT | No more index files may be opened (limit reached) |
| 34 | QBADAP | Invalid index file context pointer |
| 35 | QBUSY | File is busy |
| 36 | QNOTOP | Function prohibited in shared access mode |
| 37 | QNOBLK | No block available for data storage |
| 38 | QNEGSZ | Data block usage gone negative |
| 39 | QNOTDA | Data segment header references a non-data block: %s |
| 40 | QNOOPN | This error code is unused |
| 41 | QDLOOP | Circular data segment pointer encountered |
| 42 | QUNLCK | Unlock operation failed |
| 43 | QLRUER | LRU queue corrupt - index not in list |
| 44 | QDAERR | Unable to insert data record |
| 45 | QDNEG | Data record cannot be negative |
| 46 | QDUP | Key "key" already exists in index |
| 47 | QNOKEY | Key "key" does not exist in index |
| 48 | QNOWRT | Write access to index prohibited |
| 49 | QNOTFR | Block on free list is not marked as free |
| 50 | QBADVR | Index file is incompatible with this version: "version" |
| 51 | QDAOVR | Data capacity exceeded at block: "block" |
| 52 | QF2BIG | Index file is at maximum size |
| 53 | QBADAL | Unable to set alarm for locking |
| 54 | QDRANEG | Data record address is negative: "address" |
| 55 | QBLKSZERR | Defined block size is not a power of 2: "size" |