I think is logic is to attempt to insert a row, and if rather than
inserting it, the call returns the error condition, 'Database Full', you
remove a record and then try again (a form of error recovery), if it
succeeds, then you go on and get more data.
If full was X records, then they would ALWAYS get room to add a new
record after deleting one. Since the reported issue is that it can
require the deletion of possibly very many records to get space to
succeed tells me that 'full' is size based (maybe a max number of
pages). If the record being added is on the larger size of all the 'same
sized' records, then you need to keep deleting records until you get one
that big, or delete two that are consecutive so that you get a large
enough space, or you delete a records that has some spare space next to
it giving enough room.
One issue with this definition is that you can't tell if the database is
currently full except by trying to add the record (or knowing a LOT of
internal details of record storage), which is what the code is doing.
On 4/4/19 9:19 AM, Stephen Chrzanowski wrote:
> This almost sounds like "Full" is a software limitation, in that your
> application is specifying that "Full" means you can only have "X" number of
> rows.
>
> If you're looking to remove data, I'd suggest that you find some way to
> isolate the oldest record, either by a row identifier (Like an ID field
> that's using auto-increment) or a date/time stamp (Assigned by
> current_timestamp).
>
> Also, your logic is backwards in your pseudo-code. You should check the
> status of the database before you do any kind of insert. The reason is, if
> you insert into an already full database, then you're database is over-full
> at that point. Also, your pseudo-code has two conditions to look at... Do
> this forever, and repeat while status is full. Not to mention, if your
> database is messed up and nothing can be inserted even though the table is
> empty, you've introduced a lockup.
>
> What I think you're looking more for is:
>
> while (dbStatus() == full) {
> remove_one_row_from_db();
> }
> result=insert_1_row_to_db();
> if (result != resOK) {
> die("uhh.. Problem with the database?");
> }
>
>
> On Thu, Apr 4, 2019 at 6:53 AM Arthur Blondel <arthur5blon...@gmail.com>
> wrote:
>
>> Hello
>>
>> When I try to insert new data to a full SQLite database, I need to remove
>> much more than really needed. I'm doing the following:
>>
>> while(1) {
>> do {
>> status = insert_1_row_to_db();
>> if (status == full) {
>> remove_one_row_from_db();
>> }
>> } while (status == full);}
>>
>> The inserted data has always the same size. When the database is full,
>> removing only one row is enough to insert the new one. But after a while, I
>> need to remove 30, 40 and even more the 100 rows to be able to insert one
>> new row. Is it the correct behavior of SQLite? Is there a way to remove
>> only what is needed and no more? Thanks
>> _______________________________________________
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>> sqlite-users@mailinglists.sqlite.org
>> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>>
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Richard Damon
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