Db.Query Class

make a copy of all the sub-objects, including the clauses, parameters, etc.

Used to determine if there is a shardIndex to be used for this type of class

Calculates which shards the query should be issued to, based on those "WHERE" criteria that were specified in a structured way. Used mostly by .execute(), but you can call it too, to see how a query would be executed. Here is sample shards config:

NOTE: "fields" shall be an object with keys as fields names and values containing hash definition in the format "type%length" where type is one of 'md5' or 'normalize' and length is hash length hash definition can be empty string or false. In such case 'md5%7' is used

NOTE: "partition" can be an array. In such case shards shall be named after partition points

"Streams": {
    "prefix": "streams_",
    "dsn": "mysql:host=127.0.0.1;dbname=DBNAME",
    "username": "USER",
    "password": "PASSWORD",
    "driver_options": {
        "3": 2
    },
    "shards": {
        "alpha": {
            "prefix": "alpha_",
            "dsn": "mysql:host=127.0.0.1;dbname=SHARDDBNAME",
            "username": "USER",
            "password": "PASSWORD",
            "driver_options": {
                "3": 2
            }
        },
        "betta": {
            "prefix": "betta_",
            "dsn": "mysql:host=127.0.0.1;dbname=SHARDDBNAME",
            "username": "USER",
            "password": "PASSWORD",
            "driver_options": {
                "3": 2
            }
        },
        "gamma": {
            "prefix": "gamma_",
            "dsn": "mysql:host=127.0.0.1;dbname=SHARDDBNAME",
            "username": "USER",
            "password": "PASSWORD",
            "driver_options": {
                "3": 2
            }
        },
        "delta": {
            "prefix": "delta_",
            "dsn": "mysql:host=127.0.0.1;dbname=SHARDDBNAME",
            "username": "USER",
            "password": "PASSWORD",
            "driver_options": {
                "3": 2
            }
        }
    },
    "indexes": {
        "Stream": {
            "fields": {"publisherId": "md5", "name": "normalize"},
            "partition": {
                "0000000.       ": "alpha",
                "0000000.sample_": "betta",
                "4000000.       ": "gamma",
                "4000000.sample_": "delta",
                "8000000.       ": "alpha",
                "8000000.sample_": "betta",
                "c000000.       ": "gamma",
                "c000000.sample_": "delta"
            }
        }
    }
}