Hi team TAPIS -
I have extracted the important bits of draft TAP information schemas which we each submitted, and summarize these below to make it easier to compare each shema (minus the VOTable formatting which is a detail at this point).
There is a lot of overlap, and it would not be difficult to combine these, if some questions were decided, e.g., 1) follow VOTable or IS conventions for naming, datatypes, etc.?; 2) should we support the registry view at this level, e.g., Role, Std? (note Role can also be useful to interpret standard Views); 3) should we differentiate between PARAM and FIELD at this level, or consider both to be like a VOTable FIELD (with PARAM being a VOTable feature)?; 4) include SQL-IS features such as "catalog_name", "schema_name", etc.?; 5) how to handle nil/nullable?
The NRAO systems are being updated this weekend and email is currently down, so I have no idea whether this email will actually go out, or whether anything else TAP-related was posted today. I will check later when email is restored to see whether the mail was sent.
DT Schema
TABLES
Id Unique Table ID
Name Table name (Required)
Type Table type (base, view) (Required)
Role How table is used, e.g., "out"
Ucd Can a table actually have a UCD?
Utype UTYPE can apply to a table
Description Short one line table description
COLUMNS
Id Unique column ID
TableName Table to which column belongs (Required)
Name Column name (Required)
Datatype Datatype (as in VOTable + "string") (Required)
Arraysize Arraysize (as in VOTable)
ColumnType Column type (as in VOTable Field, Param)
Std Standard column (boolean)
Value Value if ColumnType=Param (fixed value)
Ucd UCD for column
Utype UTYPE for column
Unit UNIT for column
Description Brief one-line description of column
Note 1: Role and Std are provided for the registry view Note 2: Note that Columns can describe VOTable Param as well as Field
FO Schema
(VOTable table header(s), plus the following for the schema approach)
TABLES
Name Table name
Description Table description
COLUMNS
Name Column label
Ucd UCD1_ representation
Type Data-type
Width Length for strings/blobs
Unit Units of the data (controlled)
Description Detailed explanation of the column
Note 1: Here Columns describes only a single table
RP Schema
TABLES
Id Unique ID for the table
Name The name of the table
Ucd The UCD describing the table
Utype The UTYPE describing the table
Nrows The number of rows in the table (if static/known)
Description A description of what the table contains
COLUMNS
table_ID ID of the table this column belongs to
Id Unique ID for the column
Name The name of the column
Ucd The UCD describing the column
Utype The UTYPE describing the column
Unit The unit associated with values in this column
Datatype The datatype of values in this column
Arraysize Number and array "shape" of values in this column
Precision The precision description for values in this column
Width The number of characters used to encode the value
Description A description of what the column contains
Note 1: A SQL-like query of Columns "where tableName = foo" will not work here as an internal ID is used instead of the table name.
Note 2: Things like ID should not be XML specific, as we may need to represent this information in other contexts.
PD Schema
(This is based on a subset of the SQL information schema rather than
the VOTable model, with some additions)
TABLES
catalog_name The name of the catalog containing the table
schema_name The name of the schema for the table
table_name The name of the table itself
table_type The type of the table: TABLE or VIEW
ucd The UCD describing the table
utype The UTYPE describing the table
description A description of what the table contains
COLUMNS
catalog_name The name of the catalog containing the table
schema_name The name of the schema for the table
table_name The name of the table itself
column_name The name of the column
ordinal_position The position of this column in the table
is_nullable Whether this column may hold NULL values
datatype The datatype of values in this column
ucd The UCD describing the column
utype The UTYPE describing the column
unit The unit associated with values in this column
description A description of what the column contains
Note 1: Catalog/Schema are included here and may be needed in TAP to reference tables in different "databases" (such as a local DBMS or a named VOSpace).
Note 2: Does "datatype" refer to the SQL datatype or the VOTable datatype? Received on 2007-10-07Z00:42:05