block_lookup: Probe a materialized block by column value
In vectra: Columnar Query Engine for Larger-than-RAM Data

block_lookup

R Documentation

Probe a materialized block by column value

Description

Performs a hash lookup on a string column of a materialized block. Returns all rows where the column value matches one of the query keys. Hash indices are built lazily on first use and cached for subsequent calls.

Usage

block_lookup(block, column, keys, ci = FALSE)

Arguments

`block`	A `vectra_block` from `materialize()`.
`column`	Character scalar. Name of the string column to match against.
`keys`	Character vector. Query values to look up.
`ci`	Logical. Case-insensitive matching (default `FALSE`).

Value

A data.frame with column query_idx (1-based position in keys) plus all columns from the block, for each (query, block_row) match pair.

Examples


f <- tempfile(fileext = ".vtr")
df <- data.frame(taxonID = 1:2,
                 canonicalName = c("Quercus robur", "Pinus sylvestris"))
write_vtr(df, f)
blk <- materialize(tbl(f))
hits <- block_lookup(blk, "canonicalName", c("Quercus robur"))
ci_hits <- block_lookup(blk, "canonicalName", c("quercus robur"), ci = TRUE)
unlink(f)

vectra documentation built on May 8, 2026, 9:06 a.m.