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TileDB Driver Schemas

Source: R/TileDBDriverSchemas.R
driver_schemas.Rd

Tune driver performance and storage characteristics: compression algorithms, compression levels, tile capacity, cell order, and tile order settings. This is useful for creating storage drivers for use cases that need different trade-offs (speed vs. compression, memory vs. disk).

Usage

driver_schemas(uri = NULL, ctx = NULL, none_filter = FALSE)

Arguments

uri

Optional URI path to TileDB driver. If not given, the default template array schemas will be used.

ctx

Optional tiledb_ctx object.

none_filter

TRUE for no filters, FALSE for default filters. Applied on default schemas and not on schemas extracted from a URI path.

Value

An object of class TileDBDriverSchemas.

Details

Use driver_schemas() to:

  • Create schemas with optional filters

  • Dynamically apply compression to individual attributes

  • Persist those customizations into the underlying TileDB arrays

Examples

ctx <- new_context()

# Create schemas without compression filters
sto_schemas <- driver_schemas(ctx = ctx, none_filter = TRUE)


# Set up a ZSTD filter with high compression
flt <- tiledb::tiledb_filter("ZSTD", ctx = ctx)
flt <- tiledb::tiledb_filter_set_option(flt,"COMPRESSION_LEVEL", 22)
fl_list <- tiledb::tiledb_filter_list(flt, ctx = ctx)

# Apply filter list to 'value' attribute (CAS storage data)
sto_schemas$SchemaData$attr_value <- fl_list

# Check 'data' schema; notice 'attr_value' has a new filter list
sto_schemas$SchemaData$schema()
#> tiledb_array_schema(
#>     domain=tiledb_domain(c(
#>         tiledb_dim(name="hash", domain=c(NULL,NULL), tile=NULL, type="ASCII", filter_list=tiledb_filter_list(c(tiledb_filter("NONE"))))
#>     )),
#>     attrs=c(
#>         tiledb_attr(name="value", type="ASCII", ncells=NA, nullable=FALSE, filter_list=tiledb_filter_list(c(tiledb_filter_set_option(tiledb_filter("ZSTD"),"COMPRESSION_LEVEL",22))))
#>     ),
#>     cell_order="COL_MAJOR", tile_order="COL_MAJOR", capacity=10000, sparse=TRUE, allows_dups=FALSE,
#>     coords_filter_list=tiledb_filter_list(c(tiledb_filter("NONE"))),
#>     offsets_filter_list=tiledb_filter_list(c(tiledb_filter("NONE"))),
#>     validity_filter_list=tiledb_filter_list(c(tiledb_filter("NONE")))
#> )