2.3.4.1 TCINFO

TCINFO is the header structure for the TC. The TCINFO is accessed using the hidUserRoot field in the HNHDR structure of the containing HN. The header contains the column definitions and other relevant data.

Unicode / ANSI:

bType (1 byte): TC signature; MUST be set to bTypeTC.

cCols (1 byte): Column count. This specifies the number of columns in the TC.

rgib (8 bytes): This is an array of 4 16-bit values that specify the offsets of various groups of data in the actual row data. The application of this array is specified in section 2.3.4.4, which covers the data layout of the Row Matrix. The following table lists the meaning of each value:

Index	Friendly name	Meaning of rgib[Index] value
0	TCI_4b	Ending offset of 8- and 4-byte data value group.
1	TCI_2b	Ending offset of 2-byte data value group.
2	TCI_1b	Ending offset of 1-byte data value group.
3	TCI_bm	Ending offset of the Cell Existence Block.

hidRowIndex (4 bytes): HID to the Row ID BTH. The Row ID BTH contains (RowID, RowIndex) value pairs that correspond to each row of the TC. The RowID is a value that is associated with the row identified by the RowIndex, whose meaning depends on the higher level structure that implements this TC. The RowIndex is the zero-based index to a particular row in the Row Matrix.

hnidRows (4 bytes): HNID to the Row Matrix (that is, actual table data). This value is set to zero if the TC contains no rows.

hidIndex (4 bytes): Deprecated. Implementations SHOULD ignore this value, and creators of a new PST MUST set this value to zero.

rgTCOLDESC (variable): Array of Column Descriptors. This array contains cCols entries of type TCOLDESC structures that define each TC column. The entries in this array MUST be sorted by the tag field of TCOLDESC.