tamcre -r record-length -l key-area-length -k key-begin-position -m max-records-count [-t] [-u hash-entry-utilization-factor [-x] [-y]] [-s] [-d TAM-data-file-name] TAM-file-name

The tamcre command creates a new TAM file based on specified options.

-r record-length~<unsigned integer> ((1-1000000000))

Specifies the record length of the TAM file.

-l key-area-length~<unsigned integer> ((1-1000000000))

Specifies the key length.

-k key-begin-position~<unsigned integer> ((1-1000000000))

Specifies the length from the beginning of a record to the key begin position.

If the -s option is specified, 0 must be specified for this option.

-m max-records-count~<unsigned integer> ((1-1000000000))

Specifies the maximum number of records in the TAM table.

-t

Specifies that the TAM table is to be created in tree format.

If this option is omitted, the TAM table will be created in hash format. When this option is omitted, the -u option must be specified.

-u hash-entry-utilization-factor~<unsigned integer> ((1-100))

Specifies the utilization factor for the index to be used as the hash area.

When this option is omitted, the -t option must be specified.

-x

When there is any initial data to create the TAM file in the hash format, the synonym area is usually optimized to reduce the size of the TAM file and amount of shared memory.

The -x option specifies not to optimize the synonym area.

Specify this option when using the TAM file as:

• The hash format TAM table to be added or deleted online by a command.
• The hash format TAM table whose records are to be added or deleted by a UAP.

-y

Changes the hash function to be used for a hash-format TAM file. Specify this option in the following cases:

• When you use a key whose key value does not change much even though the key length is rather long
• When the amount of synonym information to be acquired using the tamhsls command after the creation of a TAM file is considerably large

-s

Specifies that the key area is to be deleted from the records.

When this option is specified, the record length of the TAM file becomes "specified record length - key area length".

-d TAM-data-file-name~<path name>

Specifies a name for the file in which the TAM table data is to be stored.

When this option is omitted, a physical file only is allocated.

TAM-file-name~<path name>

Specifies the name of the OpenTP1 file system in which the TAM table is to be stored.

If an existing TAM file name is specified, an error message (KFCA02836-E) is displayed. A new TAM file name must be specified.

• If the -t and -u options are both specified, an error occurs.
• To initialize a hash type TAM file with the tamcre command, the index area as large as the maximum number of records specified in the -m option must be allocated, and the area specified in the -u option (hash entry utilization percentage) as the hash area. In addition, how many records are to be contained in the synonym area must be calculated from the data to be read from a data file, and the result allocated as the synonym area. Thus, the resulting total of records exceeds the maximum number of records specified in the -m option.
• When you specify the -y option, the hash function for retrieving records from key values changes and you can expect increased accuracy in the distribution of hash values. However, the performance of the hash function itself may decrease when compared to a hash function that is used for a TAM file without the -y option.
• The memory requirement for the tamcre command depends on the size of the TAM file to be created. Use the following formula to estimate the memory requirement (in bytes):
  400000 + A + B + C
  

  Legend:

  A: record-count x record-length. Add the value of A only when the -d option is specified.

  B: Size of the target TAM file. For the formula for estimating the TAM file size, see H.7 Estimating the size of a TAM file.

  C: record-count x 8 for a 32-bit OS; record-count x 16 for a 16-bit OS