SHOW LINEAGE

Commands › Looking around · Any caller; rows they are not granted never appear

Walks a record through the layers. DOWN (the default) starts from a model record and lists the cleaned rows, source rows and original items it was made from. UP starts from one row of a table and lists the model records built from it.

Syntax

SHOW LINEAGE OF <Entity> '<key>' [ DOWN | UP ]

SHOW LINEAGE OF <Entity> IN ( '<key>' [, ...] ) [ DOWN ]

SHOW LINEAGE OF <table> '<row id>' UP

Parameters

Parameter	Description
<Entity>	A model entity with records of its own.
'<key>'	The record's key, quoted.
IN ( '<key>', ... )	Several records walked down together: the traced body runs once for all of them. Each record's first rows carry its key in via.
<table>	tables.<source>.<table>, clean.<source>.<table>, data.<table> or <corpus>.<Entity>. A walk from a table goes UP only.
'<row id>'	The row's id: a source row's _source_key or _id, a cleaned group's _id.

Usage notes

• Columns: layer, table, row_id, source_key, via, title. layer is record (a model record), cleaned (a clean. group), source (a landed row), original (the item as the source sent it: read it with SHOW RAW) or untraced.
• DOWN rewrites the entity's body so every table it reads carries its row ids out, through derived tables, CTEs and set operations, and filters it to the key. A body that cannot be traced gives one untraced row saying why.
• UP runs the same rewritten bodies the other way, for every entity that reads the row's table (or the cleaned group the row belongs to), and then the entities built on those.
• A walk reads at most 10000 rows per step and follows at most four levels of entities built on entities.
• The MCP query tool runs this statement.
• SHOW LINEAGE OF '<_id>', with no entity or table, parses but is not implemented.

Examples

SHOW LINEAGE OF Order 'PO-1042'

layer	table	row_id	source_key	via	title
record	Order	PO-1042			PO-1042
source	tables.drive.file	f_88	drive:file:f_88		po-1042.pdf
original	tables.drive.file	f_88	drive:file:f_88

Several records at once:

SHOW LINEAGE OF Order IN ('PO-1042', 'PO-1017') DOWN

From one landed row up to what was built from it:

SHOW LINEAGE OF tables.crm.account 'crm:account:0017' UP

Not supported

Refused	Write instead
IN (...) with UP	Walk up from one row: SHOW LINEAGE OF <table> '<row id>' UP

-- Refused by the engine
SHOW LINEAGE OF Order IN ('PO-1042', 'PO-1017') UP

See also

SHOW RAW · SHOW LINKS · SHOW MODEL · CREATE ENTITY · ALTER TABLE ... NORMALISE