this commit adds the final touches to the state machine for btree_destroy and also introduces a state machine for clear_overflow_pages
this addresses the issue of IO interrupting an operation in progress and solves the following problems:
* performance issues with repeating an operation
* missing page issues with clear overflow pages
modified the btree_destroy subroutine to do an iterative DFS and use the stack cell counters to keep track of whether children have been removed. adds a unit test.
modified the Null instruction to more closely match SQLite semantics. Allows passing in a second register and all registers from r1..r2 area set to null
the command for drop table translation has been updated so that it more closely matches the semantics of SQLite's drop table command.
there are a few more things missing like ephemeral tables, destroy etc.
this is the initial commit is for the implementation of DROP TABLE. It adds support for the DROP TABLE instruction and adds a DropBTree instruction. It also implements the btree_drop method in btree.rs which makes use of free_page method which will be implemented via PR https://github.com/tursodatabase/limbo/pull/785
This is a first step to supporting [sqlite column
affinity](https://www.sqlite.org/datatype3.html) properly in limbo --
just adds an `affinity()` function to `Column` that can then be used
elsewhere
Closes#1030
We were not evaluating constant conditions (e.g '1 IS NULL')
when there were no tables referenced in the query, because
our WHERE term evaluation was based on "during which loop"
to evaluate them. However, when there are no tables, there are
no loops, so they were never evaluated.
Fix codegen for binary functions and add fuzz test for math functions
(we need to compile `rusqlite` with `-DSQLITE_ENABLE_MATH_FUNCTIONS` in
order to bundle sqlite with math functions compiled)
Reviewed-by: Jussi Saurio (@jussisaurio)
Closes#1015
Align `substr` implementation with SQLite spec
(https://www.sqlite.org/lang_corefunc.html#substr):
> The substr(X,Y,Z) function returns a substring of input string X that
begins with the Y-th character and which is Z characters long. If Z is
omitted then substr(X,Y) returns all characters through the end of the
string X beginning with the Y-th. The left-most character of X is number
1. If Y is negative then the first character of the substring is found
by counting from the right rather than the left. If Z is negative then
the abs(Z) characters preceding the Y-th character are returned. If X is
a string then characters indices refer to actual UTF-8 characters. If X
is a BLOB then the indices refer to bytes.
Reviewed-by: Jussi Saurio (@jussisaurio)
Closes#1013
According to SQLite documentation, the way to use these instructions
is to compare the seek key to the index key as you would with the
Compare opcode. The compare opcode states:
"Compare two vectors of registers in reg(P1)..reg(P1+P3-1)
(call this vector "A") and in reg(P2)..reg(P2+P3-1) ("B")."
In other words, we should compare the same number of columns from each,
not compare the entire keys.
This fixes a few Clickbench queries returning incorrect results, and
so closes#1009
---
Future work: support index seek keys that use multiple columns. Our
index seek is many times slower than SQLite because we're not utilizing
all the possible columns -- instead we just use the first index column
to seek.
I added the two opcodes as an initial step. They are pretty easy to
implement since we already have the counterparts i.e., IdxGE and IdxGT
Is there a design reason behind their omission @penberg @PThorpe92?
I noticed the same for SeekLE and SeekLT.
Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com>
Closes#1010
easy implementation, sqlite claims it is a noop now
"This pragma no longer functions. It has become a no-op. The
capabilities formerly provided by PRAGMA legacy_file_format are now
available using the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option to the
sqlite3_db_config() C-language interface."
Closes#1007
