Skip to content

Information schema doc update #10081

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
clintropolis merged 6 commits into from
Jun 30, 2020
Merged

Information schema doc update #10081

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
2cb29e6
add docs for IS_JOINABLE and IS_BROADCAST to INFORMATION_SCHEMA docs
clintropolis Jun 26, 2020
d100700
fixes
clintropolis Jun 26, 2020
246be59
oops
clintropolis Jun 26, 2020
79bfd47
revert noise
clintropolis Jun 26, 2020
2813fe4
missed one
clintropolis Jun 26, 2020
2fed396
spellbot
clintropolis Jun 26, 2020
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
25 changes: 15 additions & 10 deletions docs/querying/sql.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -921,35 +921,40 @@ SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'druid' AND TABLE_
> `APPROX_QUANTILE_DS`. Only standard SQL functions can be used.

#### SCHEMATA table
`INFORMATION_SCHEMA.SCHEMATA` provides a list of all known schemas, which include `druid` for standard [Druid Table datasources](datasource.md#table), `lookup` for [Lookups](datasource.md#lookup), `sys` for the virtual [System metadata tables](#system-schema), and `INFORMATION_SCHEMA` for these virtual tables. Tables are allowed to have the same name across different schemas, so the schema may be included in an SQL statement to distinguish them, e.g. `lookup.table` vs `druid.table`.

|Column|Notes|
|------|-----|
|CATALOG_NAME|Unused|
|SCHEMA_NAME||
|CATALOG_NAME|Always set as `druid`|
|SCHEMA_NAME|`druid`, `lookup`, `sys`, or `INFORMATION_SCHEMA`|
|SCHEMA_OWNER|Unused|
|DEFAULT_CHARACTER_SET_CATALOG|Unused|
|DEFAULT_CHARACTER_SET_SCHEMA|Unused|
|DEFAULT_CHARACTER_SET_NAME|Unused|
|SQL_PATH|Unused|

#### TABLES table
`INFORMATION_SCHEMA.TABLES` provides a list of all known tables and schemas.

|Column|Notes|
|------|-----|
|TABLE_CATALOG|Always set as 'druid'|
|TABLE_SCHEMA||
|TABLE_NAME||
|TABLE_CATALOG|Always set as `druid`|
|TABLE_SCHEMA|The 'schema' which the table falls under, see [SCHEMATA table for details](#schemata-table)|
|TABLE_NAME|Table name. For the `druid` schema, this is the `dataSource`.|
|TABLE_TYPE|"TABLE" or "SYSTEM_TABLE"|
|IS_JOINABLE|If a table is directly joinable if on the right hand side of a `JOIN` statement, without performing a subquery, this value will be set to `YES`, otherwise `NO`. Lookups are always joinable because they are globally distributed among Druid query processing nodes, but Druid datasources are not, and will use a less efficient subquery join.|
|IS_BROADCAST|If a table is 'broadcast' and distributed among all Druid query processing nodes, this value will be set to `YES`, such as lookups and Druid datasources which have a 'broadcast' load rule, else `NO`.|

#### COLUMNS table
`INFORMATION_SCHEMA.COLUMNS` provides a list of all known columns across all tables and schema.

|Column|Notes|
|------|-----|
|TABLE_CATALOG|Always set as 'druid'|
|TABLE_SCHEMA||
|TABLE_NAME||
|COLUMN_NAME||
|ORDINAL_POSITION||
|TABLE_CATALOG|Always set as `druid`|
|TABLE_SCHEMA|The 'schema' which the table column falls under, see [SCHEMATA table for details](#schemata-table)|
|TABLE_NAME|The 'table' which the column belongs to, see [TABLES table for details](#tables-table)|
|COLUMN_NAME|The column name|
|ORDINAL_POSITION|The order in which the column is stored in a table|
|COLUMN_DEFAULT|Unused|
|IS_NULLABLE||
|DATA_TYPE||
Expand Down
3 changes: 3 additions & 0 deletions website/.spelling
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,8 @@ IANA
IETF
IP
IPv4
IS_BROADCAST
IS_JOINABLE
IS0
ISO-8601
ISO8601
Expand Down Expand Up @@ -264,6 +266,7 @@ inlined
interruptible
jackson-jq
javadoc
joinable
kerberos
keystore
keytab
Expand Down