mzt

The mzt package contains optimizer tools for Materialize developers.

Installation (pyenv)

Note: This assumes that you already have pyenv and pyenv-virtualenv installed and working in your shell.

We need a Python version higher than 3.9.x

PYTHON_VERSION=3.9.5

Run the following commands whenever the contents of this folder change:

# activate mzt environment
pyenv virtualenv-delete mzt
pyenv virtualenv ${PYTHON_VERSION} mzt

# install package
pyenv activate mzt
pip install .

# install zsh shell completion
echo "$(_MZT_COMPLETE=zsh_source mzt)" > ~/.zfunc/_mzt
rm -f ~/.zcompdump; compinit

Explain Plan Dot Graphs

The explain subcommand provides facilities for deriving *.dot files from the output of an EXPLAIN ... PLAN FOR ... query. Check the command --help for details:

mzt explain --help

Example:

mzt explain query raw-plan 'select a, b from (VALUES (1, 2)) AS R(a,b)'

Output:

digraph G {
    node0 [shape = record, label=" CallTable wrap2(1, 2)\l"]
}

Explain Plan Repositories

The explain repository subcommand provides an interface for curating repositories of dot graphs for EXPLAIN ... PLAN FOR ... outputs. Check the command --help for details:

mzt explain repository --help

Example:

# set repository location 
# the value given here is used as default if the envvar
# or the --repository option are not present
export MZT_REPOSITORY="$HOME/mzt-repos/default"

# initialize repository and add some queries
mzt explain repository add 'select a, b from (VALUES (1, 2)) AS R(a,b)'
mzt explain repository add 'select b, a from (VALUES (1, 2)) AS R(a,b)'

# start a server to browse the repository
python -m http.server --directory "$MZT_REPOSITORY" 7123 > /dev/null 2>&1 &

The repository will be then available at http://localhost:7123/index.xml.

Useful Snippets

To add pretty-printed queries, write the query in a $TEMP_FILE and then run:

mzt explain repository add "$(cat $TEMP_FILE)"

To update all images in an existing repository:

for f in $(find $MZT_REPOSITORY -name 'query.sql'); do 
    mzt explain repository add "$(cat $f)";
done

To delete all images in an existing repository:

for f in $(find $MZT_REPOSITORY -name 'query.sql'); do 
    mzt explain repository remove "$(cat $f)";
done