Contact: N. West, Oxford.
Revision History:-
================
5.01 N. West First version.
Titles Files
------------
sdb_multi_file.dat
Description
-----------
Bank Number: Search strategy number. Entries in the SDMT bank link to SDMS via this number
This bank provides the information necessary to look-up a single
titles bank that is distributed across a physical set of database
files.
Data Words
---------
Data types: B(bit), I, F, D(double), H(hollerith 4 char)
Fixed length Database Header. See titles_dbhdr.html
Word Mnemonic [symbolic command] Description
---- -------- -------------------------------
KSDMS...
1 H _DB_CODE 2 character code for database e.g. ET
Programming note: In memory this word is replaced by the index
to the corresponding database in *SDB_DBF_* tables (see sdb_multi_file.com)
2 I _SS_CODE Search Strategy code:-
KSDMS_SS_HIT_AND_MISS = 0 - search every available DB starting from the latest
KSDMS_SS_FIXED = 1 - look only in a specific DB file
KSDMS_SS_RUN_RANGE = 2 - look up based on run range
KSDMS_SS_DATE_RANGE = 3 - look up based on date range
3 I _DBF_IDX Index into *SDB_DBF_* (see sdb_multi_file.com) tables corresponding to _DB_CODE
Programming note: this word is set up sdb_mf_ini - any existing value is replaced
4 Spare
.. ...
10 Spare
The remaining words depend on the Search Strategy code (KSDMS_DB_CODE):-
KSDMS_SS_HIT_AND_MISS
No further data words
KSDMS_SS_FIXED
11 I _FIXED_DB_NO The number of the fixed DB file
KSDMS_SS_RUN_RANGE
A series of 5 word entries:-
i = 0, 5, 10 ...
i+11 I _RUN_RANGE_FILE_NO The physical DB number
i+12 I _RUN_RANGE_FIRST_RUN The first run
i+13 I _RUN_RANGE_FIRST_SUBRUN The first subrun
i+14 I _RUN_RANGE_LAST_RUN The last run
i+15 I _RUN_RANGE_LAST_SUBRUN The last subrun
Note: To preserve the same results produces by the previous multi-file system
the current one does not use the _FIRST_RUN and _FIRST_SUBRUN words.
Instead it searches forwards through the list and selects the first
entry for which _LAST_RUN, _LAST_SUBRUN exceed the required one.
KSDMS_SS_DATE_RANGE
A series of 5 word entries:-
i = 0, 5, 10 ...
i+11 I _DATE_RANGE_FILE_NO The physical DB number
i+12 I _DATE_RANGE_FIRST_DATE The first date
i+13 I _DATE_RANGE_FIRST_TIME The first time
i+14 I _DATE_RANGE_LAST_DATE The last date
i+15 I _DATE_RANGE_LAST_TIME The last time
Note: To preserve the same results produces by the previous multi-file system
the current one does not use the _LAST_DATE and _LAST_TIME words.
Instead it searches backwards through the list and selects the first
entry for which _FIRST_DATE,_FIRST_TIME is less than the required one.
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