👋 Hi everyone! I'm new to signoz and decided to poke around the source code and clickhouse db schema. I have a question about database choice and database schema alignment. Clickhouse is a column-oriented database, so I'm somewhat surprised when I look at things like

signoz_traces.signoz_index_v2::tagMap

,

signoz_traces.signoz_index_v2::stringTagMap

and

signoz_traces.signoz_spans::model

that contain json-encoded string values in them. I'm sure these were deliberate choices, it would be helpful if somebody can share insights about these decisions. Thank you in advance!

The telemetry data often contains attributes that you don't know beforehand. There are handful of way to store the arbitrary key-values pairs in ClickHouse. they are maps, pariwise-array and json string. This the reason map is used.

@Srikanth Chekuri thank you for your response. I see that columns in signoz_index_v2 are of type Map. However, signoz_spans::model has type String. Do I need to run some migration to convert it to Map?