Template:ChadoTable feature

This template is a Chado Table Template. It defines a single table from the Chado schema, and every Chado table has a template like this one. This template is automatically included in two places:

1. The module page for the module the table is a part of. This is where updates and comments should be posted.
2. The Chado Tables page, which lists all tables.

You can include this template anywhere you want to show the table description.

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Table:	feature
Module:	Sequence

A feature is a biological sequence or a section of a biological sequence, or a collection of such sections. Examples include genes, exons, transcripts, regulatory regions, polypeptides, protein domains, chromosome sequences, sequence variations, cross-genome match regions such as hits and HSPs and so on; see the Sequence Ontology for more. The combination of organism_id, uniquename and type_id should be unique.

feature columns

FK	Name	Type	Description
	feature_id	serial	PRIMARY KEY
dbxref	dbxref_id	integer	An optional primary public stable identifier for this feature. Secondary identifiers and external dbxrefs go in the table feature_dbxref.
organism	organism_id	integer	UNIQUE#1 NOT NULL The organism to which this feature belongs. This column is mandatory.
	name	character varying(255)	The optional human-readable common name for a feature, for display purposes.
	uniquename	text	UNIQUE#1 NOT NULL The unique name for a feature; may not be necessarily be particularly human-readable, although this is preferred. This name must be unique for this type of feature within this organism.
	residues	text	A sequence of alphabetic characters representing biological residues (nucleic acids, amino acids). This column does not need to be manifested for all features; it is optional for features such as exons where the residues can be derived from the featureloc. It is recommended that the value for this column be manifested for features which may may non-contiguous sublocations (e.g. transcripts), since derivation at query time is non-trivial. For expressed sequence, the DNA sequence should be used rather than the RNA sequence. The default storage method for the residues column is EXTERNAL, which will store it uncompressed to make substring operations faster.
	seqlen	integer	The length of the residue feature. See column:residues. This column is partially redundant with the residues column, and also with featureloc. This column is required because the location may be unknown and the residue sequence may not be manifested, yet it may be desirable to store and query the length of the feature. The seqlen should always be manifested where the length of the sequence is known.
	md5checksum	character(32)	The 32-character checksum of the sequence, calculated using the MD5 algorithm. This is practically guaranteed to be unique for any feature. This column thus acts as a unique identifier on the mathematical sequence.
cvterm	type_id	integer	UNIQUE#1 NOT NULL A required reference to a table:cvterm giving the feature type. This will typically be a Sequence Ontology identifier. This column is thus used to subclass the feature table.
	is_analysis	boolean	NOT NULL DEFAULT false Boolean indicating whether this feature is annotated or the result of an automated analysis. Analysis results also use the companalysis module. Note that the dividing line between analysis and annotation may be fuzzy, this should be determined on a per-project basis in a consistent manner. One requirement is that there should only be one non-analysis version of each wild-type gene feature in a genome, whereas the same gene feature can be predicted multiple times in different analyses.
	is_obsolete	boolean	NOT NULL DEFAULT false Boolean indicating whether this feature has been obsoleted. Some chado instances may choose to simply remove the feature altogether, others may choose to keep an obsolete row in the table.
	timeaccessioned	timestamp without time zone	NOT NULL DEFAULT now() For handling object accession or modification timestamps (as opposed to database auditing data, handled elsewhere). The expectation is that these fields would be available to software interacting with chado.
	timelastmodified	timestamp without time zone	NOT NULL DEFAULT now() For handling object accession or modification timestamps (as opposed to database auditing data, handled elsewhere). The expectation is that these fields would be available to software interacting with chado.

Tables referencing feature via foreign key constraints:

• featuregroup
• analysisfeature
• cell_line_feature
• element
• feature_cvterm
• feature_dbxref
• feature_expression
• feature_genotype
• feature_phenotype
• feature_pub
• feature_relationship
• feature_synonym
• featureloc
• featurepos
• featureprop
• featurerange
• library_feature
• phylonode
• studyprop_feature