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The single definition of the cell_model partition key, used by the release notebook when writing and by cell_model_tiles() when reading.

Usage

cell_model_tile_sql(col = "cell_id", ncol = .CELL_GRID_NCOL)

Arguments

col

SQL expression giving the cell id, e.g. "c.cell_id"

ncol

grid width in columns (default v8's 7200; v7 is 3103 — see cell_grid_ncol())

Value

character SQL expression

Details

Note the integer division operator //: DuckDB's / is FLOAT division, which silently yields a distinct "tile" per cell (and therefore one partition per cell) if used here by mistake.

Examples

cell_model_tile_sql("cell_id")
#> (((cell_id-1)//7200)//50)*144 + (((cell_id-1)%7200)//50)
cell_model_tile_sql("cell_id", ncol = 3103)   # v7 grid
#> (((cell_id-1)//3103)//50)*62 + (((cell_id-1)%3103)//50)