Robert...EDS - questions/comments
Robert,
I have some questions/comments concerning the EDS:
1. Say I have a table with a key structure of : {atom, atom}. I insert
3 records with the following key values: {1 , 1} {1, 2} {1, 3}. I add
another 10,00 entries with other key values. I then add {1, 4} {1, 5}.
Now I want to get all records with the first key value of 1. Assuming I
use db_find_key and find and read the first three records, would I have
to read through the next 10,000 to get the last two records? If I
checked for the first key value to change and then drop out of my read
loop I would think I would miss the last two records for key value of 1.
Is this right? If so, would it be possible to add a function to
"retrieve_next_record_by_partial_key"? I suppose I could increment the
second key value by 1 and use db_find_key but what if the second key
value was not sequential?
2. Somewhat relating to question 1, if I used db_find_key with a key
value of {1, 0} (assuming there will never be a record with a second key
value of 0) I would get a negative result. If I am reading the docs
right, the negtaive number would be the record number if it were
inserted into the file. For example, if the db_find_key returned -4,
would this mean that if I were to retrieve record 4, would it have a key
value of {1, 1} (assuming key value {1, 1} is in the file)?
3. Let me say that I really like the simplicity and ease-of-use with the
EDS. I have written programs using direct calls to Borland's Database
Engine and it's not pretty.
Jonas
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