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data page dissector. fix compiler warnings

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brianb
2004-02-15 22:15:33 +00:00
parent ee53cdd230
commit d9f25cfba7
4 changed files with 109 additions and 61 deletions
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17
HACKING
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@@ -467,17 +467,20 @@ Column Type may be one of the following (not complete):
UNKNOWN_0D = 0x0D
REPID = 0x0F /* GUID */
Notes on deleted columns:
Notes on deleted and added columns: (sort of Jet4 specific)
If a fixed length column is deleted the offset_F field will contain the values
If a fixed length column is deleted the offset_F field will contain the offsets
of the original row definition. Thus is the number of columns on the row does
not match the number in the tdef, the offset_F field could be used to return
the proper data. No idea how multiple column deletions are handled, my instinct
is that Access can only handle a single column deletion event (which may involve
more than one column if new rows have not been added) without touching all the
rows.
the proper data. Columns are never really deleted in the row data. The deleted column will forever exist and be set to null for new rows.
A row may have less than max_cols columns but will never have more, as max_cols
is never decremented. If you have a table with 6 columns, delete one, and add
one, then max_cols will be 7.
For variable length columns, offset_V will hold the position in the offset table
of that column. Missing columns are set to null for new rows.
Don't know if variable columns work by the same mechanism yet. Stay tuned.
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