Description of the illustration xla

As in the previous figure (also refer to that description), this figure shows there is fixed-length data and variable-length data in a tuple tup1. This time, the variable-length data is shown to include some VARCHAR data, and the VARCHAR data is shown to begin with information about the data length.

The following equation is shown with an arrow pointing into the fixed-length data:

VarOffset=(void*)((unsigned char*)tup1 + ttXlaColDesc_t[1].offset);

The following equation is shown with an arrow pointing into the data length information in the VARCHAR data:

Column2=(char*)(DataLength +1);

The following equation is shown next to an arrow pointing from the fixed-length data into the variable-length data, at the point in the variable-length data where the VARCHAR data begins:

DataLength=(int*)((char*)VarOffset + *((int*)VarOffset))

End of description.