cli

Documentation

Index

• Variables

Variables

var (
	Main = &cobra.Command{
		Use:   "vtexplain",
		Short: "vtexplain is a command line tool which provides information on how Vitess plans to execute a particular query.",
		Long: `vtexplain is a command line tool which provides information on how Vitess plans to execute a particular query.
		
It can be used to validate queries for compatibility with Vitess.

For a user guide that describes how to use the vtexplain tool to explain how Vitess executes a particular SQL statement, see Analyzing a SQL statement.

## Limitations

### The VSchema must use a keyspace name.

VTExplain requires a keyspace name for each keyspace in an input VSchema:
` +
			"```\n" +
			`"keyspace_name": {
    "_comment": "Keyspace definition goes here."
}
` + "```" + `

If no keyspace name is present, VTExplain will return the following error:
` +
			"```\n" +
			`ERROR: initVtgateExecutor: json: cannot unmarshal bool into Go value of type map[string]json.RawMessage
` + "```\n",
		Example: "Explain how Vitess will execute the query `SELECT * FROM users` using the VSchema contained in `vschemas.json` and the database schema `schema.sql`:\n\n" +
			"```\nvtexplain --vschema-file vschema.json --schema-file schema.sql --sql \"SELECT * FROM users\"\n```\n\n" +
			"Explain how the example will execute on 128 shards using Row-based replication:\n\n" +
			"```\nvtexplain -- -shards 128 --vschema-file vschema.json --schema-file schema.sql --replication-mode \"ROW\" --output-mode text --sql \"INSERT INTO users (user_id, name) VALUES(1, 'john')\"\n```\n",
		Args:    cobra.NoArgs,
		PreRunE: servenv.CobraPreRunE,
		Version: servenv.AppVersion.String(),
		RunE:    run,
	}
)