Comment by haeseong
14 hours ago
The query speed deserves the praise, but the JSON ingestion path has quiet footguns nobody mentions here. Every numeric column comes back as a string over JSONEachRow, so a forgotten Number() cast silently turns arithmetic into string concatenation, and with input_format_skip_unknown_fields enabled a single typo in a column name drops that field with no error at all. Worth wiring an assertion that inserts a row and reads it back into CI before trusting the dashboards.
We’ve done our JSON ingestion by keeping a schema in the app for all the types we expect, and injecting the types into the query builder.
Then as needed we have materialized columns on our different tables.
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