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Suggest Blocking Rules

Source: R/il_suggest_blocking.R
il_suggest_blocking.Rd

Enumerates single-column blocking rules and ranks them by a heuristic that balances pair reduction against field coverage. Useful for choosing initial blocking rules before training.

Usage

il_suggest_blocking(
  .data,
  columns = NULL,
  con = NULL,
  link_type = c("dedupe", "link"),
  max_depth = 1L
)

Arguments

.data

A data frame, dbplyr::tbl_lazy, or character table name.

columns

Character vector of column names to evaluate. When NULL (the default), all non-ID columns are tried.

con

A DBI connection object from DBI::dbConnect(). Optional when .data is already registered in the database.

One of "dedupe" (default) or "link".

max_depth

Maximum number of columns to combine in a single blocking rule. Defaults to 1 (single-column rules only). Set to 2 to also evaluate two-column combinations.

Value

A tibble::tibble() with columns rule, n_distinct, coverage, n_pairs, pct_of_cartesian, and score, sorted by score descending. Higher scores indicate better blocking rules.

Examples

df <- data.frame(
  unique_id = 1:20,
  first_name = c(
    'John', 'Jon', 'Jane', 'Jane', 'Bob',
    'Bobby', 'Alice', 'Alicia', 'Tom', 'Thomas',
    'John', 'Jon', 'Jane', 'Janet', 'Bob',
    'Robert', 'Alice', 'Alison', 'Tom', 'Tomas'
  ),
  surname = c(
    'Smith', 'Smith', 'Doe', 'Doe', 'Jones',
    'Jones', 'Brown', 'Brown', 'White', 'White',
    'Smith', 'Smyth', 'Doe', 'Doe', 'Jones',
    'Jones', 'Brown', 'Browne', 'White', 'White'
  )
)
con <- DBI::dbConnect(duckdb::duckdb())
il_suggest_blocking(df, con = con)
#> # A tibble: 2 × 6
#>   rule       n_distinct coverage n_pairs pct_of_cartesian score
#>   <chr>           <int>    <dbl>   <int>            <dbl> <dbl>
#> 1 first_name         13        1       8             4.21 0.958
#> 2 surname             7        1      24            12.6  0.874
DBI::dbDisconnect(con, shutdown = TRUE)