MKDB

Toy database implemented for learning purposes. Almost all of the implementation
ideas come from these resources:

• SQLite 2.8.1 source code
• CMU Intro to Database Systems 2023
• CMU Intro to Database Systems 2018

Other less important resources are linked in the source code.

Compilation

Install rustup if you don't have it and then install the
nightly toolchain:

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rustup toolchain install nightly

Use cargo to compile the project:

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cargo +nightly build

Alternatively, set your default toolchain to nightly to avoid specifying
+nightly for every cargo command:

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rustup default nightly

Compiler Version

If you see any compilation errors it's probably because of the compiler
version. Run rustc +nightly --version and compare the output to the last
version used to compile and test the project:

rustc 1.78.0-nightly (9c3ad802d 2024-03-07)

Tests

Use cargo test to
run all the unit tests:

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cargo +nightly test

Unsafe

All the unsafe code
is located in ./src/storage/page.rs, which is the
module that implements slotted pages. Miri
can be used to test possible undefined behaviour bugs. Install the component
using rustup:

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rustup +nightly component add miri

Then use cargo to test the page module:

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cargo +nightly miri test storage::page::tests

The ./src/paging/ and
./src/storage/btree.rs modules are not unsafe
themselves but they heavily rely on the slotted page module so it's worth
testing them with Miri as well:

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cargo +nightly miri test paging
cargo +nightly miri test storage::btree

If all these modules work correctly without UB then the rest of the codebase
should be fine. The ultimate UB test is the ./src/db.rs module
since it's the entry point to SQL execution so it makes use of every other
module. It can be tested with Miri as well since tests are configured to run
completely in memory without files or system calls:

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cargo +nightly miri test db::tests

The rest of modules don't make any use of unsafe code so it's not necessary to
test them with Miri.

Running The Program

Use this command to start the TCP server on port 8000 (the default if not
specified):

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cargo +nightly run -- file.db 8000

file.db can be any empty file or a file previously
managed by mkdb. It works like SQLite in that regard, the difference is that
in order to use mkdb you have to connect to the server with some TCP client
that implements the network protocol described at
./src/tcp/proto.rs. The ./client package
is a console client similar to that of MySQL or any other database and can be
used like this:

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cargo +nightly run --package client -- 8000

This will connect to the mkdb server running on port 8000 and provide you with
a shell where you can type SQL and see the results of the queries.