Encrypting network traffic
It is a best practice to encrypt network traffic between the Looker application and your database. Consider one of the options that are described on the Enabling secure database access documentation page.
The Exasol JDBC drivers support encrypted connections. If you're interested, see Exasol's documentation .
Create a Looker user
First, create a designated Looker user and give it the ability to create sessions:
CREATE USER LOOKER IDENTIFIED BY "<password>";
GRANT CREATE SESSION TO LOOKER;
Give the Looker user the appropriate SELECT
permissions for the schema or tables that you plan to access from Looker:
GRANT SELECT ON <tables that will be used by LOOKER>;
Alternatively, you can grant all privileges:
GRANT ALL PRIVILEGES ON SCHEMA <YOUR_SCHEMA> TO LOOKER;
Alternatively, if you do not want to have to re-run GRANT
statements on newly created tables in the future:
GRANT SELECT ANY TABLE TO LOOKER;
Persistent derived tables
If you want to enable PDTs for your Looker connection to Exasol, run this command:
CREATE SCHEMA LOOKER_SCRATCH;
ALTER SCHEMA LOOKER_SCRATCH CHANGE OWNER LOOKER;
Alternatively, you can grant all privileges:
GRANT ALL PRIVILEGES ON SCHEMA LOOKER_SCRATCH TO LOOKER;
Enable symmetric aggregates
To allow Exasol to take advantage of symmetric aggregates
, create the hexstring2dec
function:
OPEN
SCHEMA
< YOUR_SCHEMA
> ;
create
or
replace
function
hexstring2dec
(
hexstring
in
varchar
(
32
))
return
decimal
(
36
,
0
)
is
pos
smallint
;
current_hexstring
char
(
1
);
current_hexstring_dec
smallint
;
hexstring_length
smallint
;
res
decimal
(
36
,
0
);
begin
if
hexstring
is
null
then
return
null
;
end
if
;
hexstring_length
:
=
length
(
hexstring
);
res
:
=
0
;
pos
:
=
1
;
while
pos
< =
hexstring_length
do
current_hexstring
:
=
substr
(
hexstring
,
pos
,
1
);
if
current_hexstring
in
(
'A'
,
'B'
,
'C'
,
'D'
,
'E'
,
'F'
)
then
current_hexstring_dec
:
=
ascii
(
current_hexstring
)
-
ascii
(
'A'
)
+
10
;
else
current_hexstring_dec
:
=
to_number
(
current_hexstring
);
end
if
;
res
:
=
(
res
*
16
)
+
current_hexstring_dec
;
pos
:
=
pos
+
1
;
end
while
;
return
res
;
end
hexstring2dec
;
/
GRANT
EXECUTE
ON
FUNCTION
hexstring2dec
;
Creating the Looker connection to your database
Follow these steps to create the connection from Looker to your database:
- In the Adminsection of Looker, select Connections, and then click Add Connection.
-
Select Exasolfrom the Dialectdrop-down menu.
-
Fill out the connection details. The majority of the settings are common to most database dialects. See the Connecting Looker to your database documentation page for information.
-
To verify that the connection is successful, click Test. See the Testing database connectivity documentation page for troubleshooting information.
-
To save these settings, click Connect.
Feature support
For Looker to support some features, your database dialect must also support them.
Exasol supports the following features as of Looker 26.2:
| Feature | Supported? |
|---|---|
| Looker (Google Cloud core) | |
| Symmetric aggregates | |
| Derived tables | |
| Persistent SQL derived tables | |
| Persistent native derived tables | |
| Stable views | |
| Query killing | |
| SQL-based pivots | |
| Timezones | |
| SSL | |
| Subtotals | |
| JDBC additional params | |
| Case sensitive | |
| Location type | |
| List type | |
| Percentile | |
| Distinct percentile | |
| SQL Runner Show Processes | |
| SQL Runner Describe Table | |
| SQL Runner Show Indexes | |
| SQL Runner Select 10 | |
| SQL Runner Count | |
| SQL Explain | |
| OAuth 2.0 credentials | |
| Context comments | |
| Connection pooling | |
| HLL sketches | |
| Aggregate awareness | |
| Incremental PDTs | |
| Milliseconds | |
| Microseconds | |
| Materialized views | |
| Period-over-period measures | |
| Approximate count distinct |
