Table operations overview
For the concepts behind table operations — immutability, formulas, dependencies — see Understanding the Table API. This page is a quick-reference index of what's available; each guide linked below covers its operation in full, with examples.
Quick reference
| I want to... | Use this |
|---|---|
| Keep rows matching a condition | where("condition") |
| Get first/last N rows | head(n) / tail(n) |
| Add columns (stored) | update(["NewColumn = formula"]) |
| Add columns (computed on demand) | update_view(["NewColumn = formula"]) |
| Keep only specific columns | select(["Column1", "Column2"]) |
| Compute specific columns on demand, dropping the rest | view(["Column1", "NewColumn = formula"]) |
| Sort by column | sort("Column") |
| Sort in reverse order | sort_descending("Column") |
| Join lookup data | natural_join(other, on=["Key"]) |
| Join requiring exactly one match | exact_join(other, on=["Key"]) |
| Cross or key-matched join | join(other, on=["Key"]) |
| Match on a timestamp/ordered key | aj(other, on=["Key"]) |
| Aggregate by groups | agg_by([agg.sum_(...)], by=["Key"]) |
Diving deeper: API references
When you need complete method signatures, parameter details, or edge case behavior:
- Pydoc — deephaven.table.Table: All Python Table methods with type hints and docstrings
- Javadoc — TableOperations: The operation contracts that define behavior across all languages
The reference documentation for each operation (e.g., where, update) also links to the relevant Pydoc and Javadoc.
A quick reference for table operations