abstract persistent class %Library.Persistent extends %Library.SwizzleObject
SQL Table Name: %Library.PersistentThe %Persistent class provides the basic mechanism by which objects are stored to and retrieved from a database.
If a persistent class uses %Library.CacheStorage then the DEFAULTGLOBAL parameter is used as the default global root for the values of the storage keywords COUNTERLOCATION, DATALOCATION, IDLOCATION, INDEXLOCATION and STREAMLOCATION in the active storage definition. DEFAULTGLOBAL is only used to generate location keyword values that are not already defined. The location value is constructed by adding a location type to the end of DEFAULTGLOBAL. For example, if DEFAULTGLOBAL = "^GL.Account" the compiler will generate DATALOCATION = ^GL.AccountD.
If USEEXTENTSET is true, then DEFAULTGLOBAL is used as the default extent location.
The location types are:
^OBJ.DSTIME(ExtentName,DSTIME,objectID) = filing operation
For DSTIME=AUTO the DSTIME value is recorded in ^OBJ.DSTIME and is set by the consumer of DSTIME data.
Refer to %DeepSee documentation for more information on how DSTIME is used by %DeepSee.
The filing operations are:
If the DSTIME parameter is set to MANUAL then the user is responsible for journaling object filing operations.
Persistent classes should define a value of for EXTENTQUERYSPEC if they wish to include additional properties in their built-in Extent query.
For example, a class that expects to have about 1,000,000 instances should define:
If a persistent class uses %Library.CacheStorage then the USEEXTENTSET parameter is used to specify the global naming strategy used by the default storage class (%Library.CacheStorage). If TRUE, then global names are generated for each index that is not already allocated a LOCATION in the active storage definition.
If the storage definition specifies EXTENTLOCATION then that value is used as the base reference for all globals assigned to indices that do not have an explicit LOCATION assigned.
The global name generator for USEEXTENTSET = TRUE honors the package prefix defined in the Package Definition. If none is defined then the package prefix is generated using a based-62 encoded integer produced from CRC32 of the package name. The specific class identifier is generated from the unqualified class name using the same hash (class->crc32->base62) to form EXTENTLOCATION. Specific index suffixes are produced using a generated offset that is local to the first persistent class with an enumerated extent in which the index appears (either defined or inherited).
There are several factors that influence the generation of EXTENTLOCATION:
- If the EXTENTLOCATION keyword is defined then its value is used,
- If the DEFAULTGLOBAL class parameter is defined then its value is used,
- otherwise, the value is generated as two dot delimited segments. The first segment is either the defined package prefix retrieved from the package definition global or, if none is defined, a hash of the package name. The second segment is generated by a hash of the unqualified class name. The hash used is a base 62 encoded CRC32 of the value. For example, Sample.Person produces ^EW3K.wPC9 if no package prefix is defined.
EXTENTLOCATION is specific to each class. When a persistent class extends another persistent class, forming a subextent, then the subclass's EXTENTLOCATION is specific to that subclass. The index location for any inherited index is already defined specifically in the super class so the subclass's EXTENTLOCATION will only be used as the base for any index that originates in the subclass. For example, Sample.Employee extends Sample.Person. The EXTENTLOCATION generated for Sample.Person is ^EW3K.wPC9 and the EXTENTLOCATION for Sample.Employee is ^EW3K.D1Ex. Since Sample.Employee inherits several indices from Sample.Person, the global name assigned to each of those indices is already defined and inherited by Sample.Employee. However, any index defined in Sample.Employee and not inherited from Sample.Person will be assigned a global name based on Sample.Employee's EXTENTLOCATION, not on Sample.Person's EXTENTLOCATION. In other words, the EXTENTLOCATION storage keyword is not inherited.
The following tables show the indices and locations for Sample.Person and Sample.Employee. Notice the last index in the Sample.Employee table:
|Class = Sample.Person|
|Class = Sample.Employee extends Sample.Person|
Any generated global index locations and EXTENTLOCATION are updated back into the active storage definition after the class is compiled.
If USEEXTENTSET is FALSE, then global names are generated using the package-hash.class-hashSuffix strategy. For example, ^Sample.PersonD and ^Sample.PersonI("SSNKey") are globals used by Sample.Person and specific index structures are all stored in ^Sample.PersonI with the index name used as the first subscript.
Builds entries for each index specified in the pIndexList argument. If pIndexList is empty then all indices that originate in the class are rebuilt. If there are other bitmap indexes specified in pIndexList and there is a bitmap extent index defined for the class then it will be implicitly included in pIndexList. If the bitmap extent index is included then the bitmap extent index for each subextent is also built.
If pAutoPurge is true then the indices contained in pIndexList will be purged before they are built as long as no range is specified, if a range is specified we will skip any purge. The default is TRUE (1).
If pLockFlag is one (1) then an extent lock will be acquired before the indices are built. If the lock cannot be acquired then an error is returned. The lock is released after the index build is completed. If pLockFlag is two (2) then a lock is acquired prior to filing indices for that instance and it is released as soon the indices for that instance are filed. If it is zero (0) then no locks are used while filing the indices. If it is three (3) then a shared extent lock will be acquired before the indices are built and released upon completion.
If pJournalFlag is false then journaling is disabled for the processes used to build the indices (except where the database is in a Mirror). If this flag is true then the journal status is not altered during BuildIndices(). The default value of this argument is 1 (TRUE).
pStartID and pEndID define a range of IDs for which indices will be built. The range is inclusive. If the starting ID is null then the range begins at the first ID defined in the extent. If the ending ID is null then the range ends at the last ID defined in the extent.
If pIgnoreIndexList is defined, it should be a $listbuild of index names that should not be built. This argument allows you to build all indices except those defined in pIgnoreIndexList. The default value of this argument is "", which means all indices, or all indices specified in pIndexList, will be built.
If your index is corrupt running this function will not fix the corruption unless you rebuild the entire index and purge the existing indexes. If you have inserted some new items but have deferred building the index for these new items then you can run %BuildIndices on this range oif IDs to add the index entries for these new items.