1. Previously compound select would not start a transaction if
the rightmost subselect had no table references, e.g.
SELECT * FROM t UNION VALUES(1)
2. Previously the column names for the query were taken from the
rightmost subselect - instead, they should be taken from the
leftmost subselect.
Currently LIMIT 0 jumps to "after the main loop", and it is done
before ORDER BY and GROUP BY cursor have had a chance to be initialized,
which causes a panic.
Simplest fix for now is to delay the LIMIT initialization.
Closes#3687 .
Previously, the `try_fold_expr_to_i64` function casted `NULL` as `0`
when evaluating expressions in `LIMIT` or `OFFSET` clauses. I removed
this function since evaluating the expression directly and relying on
the MustBeInt operation for casting seems to handle everything.
Closes#3695
Made a new PR based on @sivukhin 's PR #2869 that had a lot of
conflicts. You can check out the PR description from there.
## The main idea is:
Before, if we had an index on `x` and had a query like `WHERE x > 100
and x < 200`, the plan would be something like:
```
- Seek to first row where x > 100
- Then, for every row, discard the row if x >= 200
```
This is highly wasteful in cases where there are a lot of rows where `x
>= 200`. Since our index is sorted on `x`, we know that once we hit the
_first_ row where `x >= 200`, we can stop iterating entirely.
So, the new plan is:
```
- Seek to first row where x > 100
- Then, iterate rows until x >= 200, and then stop
```
This also improves the situation for multi-column indexes. Imagine index
on `(x,y)` and a condition like `WHERE x = 100 and y > 100 and y < 200`.
Before, the plan was:
```
- Seek to first row where x=100 and y > 100
- Then, iterate rows while x = 100 and discard the row if y >= 200
- Stop when x > 100
```
This also suffers from a problem where if there are a lot of rows where
`x=100` and `y >= 200`, we go through those rows unnecessarily. The new
plan is:
```
- Seek to first row where x=100 and y > 100
- Then, iterate rows while x = 100 and y < 200
- Stop when either x > 100 or y >= 200
```
Which prevents us from iterating rows like `x=100, y = 666`
unnecessarily because we know the index is sorted on `(x,y)` - once we
hit any row where `x>100` OR `x=100, y >= 200`, we can stop.
Closes#3644
Extracts the core logic of IN from the conditional version, and uses the
conditional metadata to determine the jump. Then Uses the AddImm
operator we just added to force the integer conversion at the end (like
SQLite does).
`BTreeTable::to_sql` makes us incompatible with SQLite by losing e.g. the original whitespace provided during the CREATE TABLE command.
For now let's fix our tests by regex-replacing every CREATE TABLE in
the entire repo to have exactly 1 space after the table name in the
CREATE TABLE statement.
I ended up hitting #1974 today and wanted to fix it. I worked with
Claude to generate a more comprehensive set of queries that could fail
aside from just the insert query described in the issue. He got most of
them right - lots of cases were indeed failing. The ones that were
gibberish, he told me I was absolutely right for pointing out they were
bad.
But alas. With the test cases generated, we can work on fixing it. The
place where the assertion was hit, all we need to do there is return
true (but we assert that this is indeed a string literal, it shouldn't
be anything else at this point).
There are then just a couple of places where we need to make sure we
handle double quotes correctly. We already tested for single quotes in a
couple of places, but never for double quotes.
There is one funny corner case where you can just select "col" from tbl,
and if there is no column "col" on the table, that is treated as a
string literal. We handle that too.
Fixes#1974
