DBMS_LOB
The DBMS_LOB
package provides subprograms to operate on BLOBs, CLOBs, and NCLOBs, including temporary LOBs, in TimesTen Classic.
Note:
-
TimesTen does not support
DBMS_LOB
subprograms intended specifically for BFILEs, SecureFiles (including Database File System features), or inserting or deleting data fragments in the middle of a LOB. -
DBMS_LOB
procedures and functions are supported for both TimesTen LOBs and passthrough LOBs, which are LOBs in Oracle Database accessed through TimesTen and exposed as TimesTen LOBs. Note, however, thatCREATETEMPORARY
can only be used to create a temporary LOB in TimesTen. If a temporary passthrough LOB is created using some other mechanism, such as SQL,ISTEMPORARY
andFREETEMPORARY
can be used on that LOB.As with TimesTen local LOBs, a locator for a passthrough LOB does not remain valid past the end of the transaction.
In addition to copying from one TimesTen LOB to another,
COPY
can copy from a TimesTen LOB to a passthrough LOB, from a passthrough LOB to a TimesTen LOB, or from one passthrough LOB to another passthrough LOB. An attempt to copy a passthrough LOB to a TimesTen LOB when the passthrough LOB is larger than the TimesTen LOB size limit results in an error. (COPY Procedures in Oracle TimesTen In-Memory Database PL/SQL Packages Reference provides examples for copying LOBs.)See Passthrough LOBs.
Table 7-1 describes the supported DBMS_LOB
subprograms.
Table 7-1 DBMS_LOB Subprograms
Subprogram | Description |
---|---|
|
Appends the contents of the source LOB to the destination LOB. |
|
Closes a previously opened LOB. |
|
Compares two entire LOBs or parts of two LOBs. |
|
Reads character data from a source |
|
Takes a source |
|
Copies all or part of the source LOB to the destination LOB. |
|
Creates a temporary LOB in the temporary data region. Any of the durations supported by Oracle Database is permitted ( |
|
Erases all or part of a LOB. |
|
Frees a temporary LOB in the temporary data region. |
|
Returns the storage limit for the LOB type of the specified LOB. |
|
In TimesTen, this simply returns the value 32 KB for interoperability. Do not rely on this value for performance tuning. |
|
Returns the length of the LOB value, in bytes for a BLOB or characters for a CLOB or NCLOB. |
|
Returns the matching position of the nth occurrence of the pattern in the LOB. |
|
Checks to see if the LOB was already opened using the input locator. |
|
Checks whether the locator is pointing to a temporary LOB. |
|
Opens a LOB (persistent or temporary) in the indicated mode, read/write or read-only. Note: Opening a LOB is similar conceptually, but not technically, to opening a file. Opening a LOB is more like a hint regarding resources to be required. |
|
Reads data from the LOB starting at the specified offset. |
|
Returns part of the LOB value starting at the specified offset. |
|
Trims the LOB value to the specified shorter length. |
|
Writes data to the LOB from a specified offset. |
|
Writes a buffer to the end of a LOB. |