Conversion of max_rows_per_page to exp_row_size

If a max_rows_per_page value is set for an allpages-locked table, the value is used to compute an expected row size during the alter table...lock command. The formula is shown in Table 3-7.

Table 3-7: Conversion of max_rows_per_page to exp_row_size

Value of max_rows_per_page

Value of exp_row_size

0

Percentage value set by default exp_row_size percent

1 – 254

The smaller of:

  • Maximum row size

  • (logical page size) – (page header overheads) / max_rows_per_page

For example, if max_rows_per_page is set to 10 for an allpages-locked table on a server configured for 2K pages with a maximum defined row size of 300 bytes, the exp_row_size value is 200 (2002/10) after the table is altered to use data-only locking.

If max_rows_per_page is set to 10, but the maximum defined row size is only 150, the expected row size value is set to 150.