Hi, all.

I’m trying to add a MonetDB interface to VoltTron, a Python based server for building and energy management systems.

To that end I have to be able to use some of the mclient commands from it, for example, to check if a table exists (\d ), from Python.

IIUC, monetdb.mapi.Connection objects should enable me to do that, but I have no idea how.

A second question is about performance. The existing databse schema for this product looks like this in MonetDB:

CREATE TABLE "voc"."data_test" (

                "ts"           TIMESTAMP(3)  NOT NULL,

                "topic_id"     INTEGER       NOT NULL,

                "value_string" CHARACTER LARGE OBJECT NOT NULL,

                CONSTRAINT "data_test_topic_id_ts_unique" UNIQUE ("topic_id", "ts")

);

There’s a time stamp and topic ID, and SELECT queries are almost always for a narrow range in time, and a small set of topic IDs (usually a set of one).

The “value_string” is there because values in the topics can range in type, but are almost always floats. Can I expect MonetDB’s performance to be good

For this use case? Or should I force the value_string to a float?