arrowscan

type ColumnTypeInfo ¶

type ColumnTypeInfo struct {
	// DatabaseTypeName is the Databricks type name (e.g. "BIGINT", "DECIMAL"),
	// matching the Thrift path; "" for a type with no Databricks name.
	DatabaseTypeName string
	// ScanType is the Go type database/sql recommends scanning the column into,
	// matching the Thrift path.
	ScanType reflect.Type
	// Length / HasLength report a variable-length column's unbounded length
	// (math.MaxInt64), matching Thrift; fixed-width types report (0, false).
	Length    int64
	HasLength bool
}

ColumnTypeInfo is the per-column metadata database/sql surfaces through sql.ColumnType. The kernel derives it from the result's Arrow schema via ColumnTypeInfoFor — the mapping the value scanner and type reporter share, kept byte-identical to the Thrift backend (guarded by the coltype parity tests).

func ColumnTypeInfoFor(dt arrow.DataType) ColumnTypeInfo

func ColumnTypeInfoForField(field arrow.Field) ColumnTypeInfo

type ScanOptions ¶ added in v1.17.0

type ScanOptions struct {
	DecimalAsFloat   bool
	GeospatialBinary bool
}

ScanOptions controls top-level result adaptations that cannot be inferred from an Arrow array alone. Logical GEOMETRY / GEOGRAPHY identity lives on the enclosing schema Field, so kernelRows sets GeospatialBinary only for a field carrying that metadata and a physical struct value.

type StructKeyCache ¶

type StructKeyCache struct {
	// contains filtered or unexported fields
}

StructKeyCache memoizes the JSON-escaped `"name":` prefixes for a struct type, so writeStructJSON doesn't re-marshal constant field names on every row. It is caller-owned and must be scoped to a single result set (e.g. one driver.Rows) and discarded with it — NOT a process-global, which would leak.

The Arrow C Data import allocates a fresh *StructType per batch, so a key is only ever hit within the batch that created it: across a multi-batch result the map would otherwise accrue one never-evicted entry per batch for the whole Rows lifetime. Callers should therefore Reset() the cache at each batch boundary — all rows of a batch share one imported Record, so the intra-batch win (escape each field name once per batch, not once per row) is fully preserved while the map stays bounded to a single batch's struct types. A nil cache is valid: rendering just recomputes the keys inline.

func NewStructKeyCache() *StructKeyCache

func (c *StructKeyCache) Reset()