supabase-cli/internal/inspect/cache/cache.go

57 lines
1.7 KiB
Go

package cache
import (
"context"
_ "embed"
"fmt"
"github.com/go-errors/errors"
"github.com/jackc/pgconn"
"github.com/jackc/pgx/v4"
"github.com/spf13/afero"
"github.com/supabase/cli/internal/migration/list"
"github.com/supabase/cli/internal/utils"
"github.com/supabase/cli/pkg/pgxv5"
)
//go:embed cache.sql
var CacheQuery string
type Result struct {
Name string
Ratio float64
}
func Run(ctx context.Context, config pgconn.Config, fsys afero.Fs, options ...func(*pgx.ConnConfig)) error {
// Ref: https://github.com/heroku/heroku-pg-extras/blob/main/commands/cache_hit.js#L7
conn, err := utils.ConnectByConfig(ctx, config, options...)
if err != nil {
return err
}
defer conn.Close(context.Background())
rows, err := conn.Query(ctx, CacheQuery)
if err != nil {
return errors.Errorf("failed to query rows: %w", err)
}
result, err := pgxv5.CollectRows[Result](rows)
if err != nil {
return err
}
// TODO: implement a markdown table marshaller
table := "|Name|Ratio|OK?|Explanation|\n|-|-|-|-|\n"
for _, r := range result {
ok := "Yup!"
if r.Ratio < 0.94 {
ok = "Maybe not..."
}
var explanation string
if r.Name == "index hit rate" {
explanation = "This is the ratio of index hits to index scans. If this ratio is low, it means that the database is not using indexes effectively. Check the `index-usage` command for more info."
} else if r.Name == "table hit rate" {
explanation = "This is the ratio of table hits to table scans. If this ratio is low, it means that your queries are not finding the data effectively. Check your query performance and it might be worth increasing your compute."
}
table += fmt.Sprintf("|`%s`|`%.6f`|`%s`|`%s`|\n", r.Name, r.Ratio, ok, explanation)
}
return list.RenderTable(table)
}