31 Aug 2017

psql \d now supports DISTKEY / SORTKEY / ENCODING (in Redshift)

This is in continuation of my work for (my forked version of) psql to better support Redshift (read more here).

Now \d table provides some additional Redshift specific table properties such as:
  • DISTKEY
  • SORTKEY
  • COMPRESSION (ENCODING)
  • ENCRYPTION
Sample:

t3=# CREATE TABLE customer(
  custkey   SMALLINT                ENCODE delta NOT NULL,
  custname  INTEGER DEFAULT 10      ENCODE raw NULL,
  gender    BOOLEAN                 ENCODE RAW,
  address   CHAR(5)                 ENCODE LZO,
  city      BIGINT identity(0, 1)   ENCODE DELTA,
  state     DOUBLE PRECISION        ENCODE Runlength,
  zipcode   REAL,
  tempdel1  DECIMAL                 ENCODE Mostly16,
  tempdel2  BIGINT                  ENCODE Mostly32,
  tempdel3  DATE                    ENCODE DELTA32k,
  tempdel4  TIMESTAMP               ENCODE Runlength,
  tempdel5  TIMESTAMPTZ             ENCODE DELTA,
  tempdel6  VARCHAR(MAX)            ENCODE text32k,
  start_date VARCHAR(10)            ENCODE TEXT255
)
DISTSTYLE KEY
DISTKEY (custname)
INTERLEAVED SORTKEY (custkey, custname);
CREATE TABLE
t3=# \d customer
                                                                   TABLE "public.customer"
   Column   |            Type             | Encoding  | DistKey | SortKey | Preload | Encryption | Collation | Nullable |              Default
------------+-----------------------------+-----------+---------+---------+---------+------------+-----------+----------+------------------------------------
 custkey    | smallint                    | delta     | f       | 1       | f       | none       |           | not null |
 custname   | integer                     | none      | t       | 2       | f       | none       |           |          | 10
 gender     | boolean                     | none      | f       | 0       | f       | none       |           |          |
 address    | character(5)                | lzo       | f       | 0       | f       | none       |           |          |
 city       | bigint                      | delta     | f       | 0       | f       | none       |           |          | "identity"(493983, 4, '0,1'::text)
 state      | double precision            | runlength | f       | 0       | f       | none       |           |          |
 zipcode    | real                        | none      | f       | 0       | f       | none       |           |          |
 tempdel1   | numeric(18,0)               | mostly16  | f       | 0       | f       | none       |           |          |
 tempdel2   | bigint                      | mostly32  | f       | 0       | f       | none       |           |          |
 tempdel3   | date                        | delta32k  | f       | 0       | f       | none       |           |          |
 tempdel4   | timestamp without time zone | runlength | f       | 0       | f       | none       |           |          |
 tempdel5   | timestamp with time zone    | delta     | f       | 0       | f       | none       |           |          |
 tempdel6   | character varying(65535)    | text32k   | f       | 0       | f       | none       |           |          |
 start_date | character varying(10)       | text255   | f       | 0       | f       | none       |           |          |

Now that a few 'ToDos' are listed on Github Issues, next would probably involve working on this ticket, which aims at elaborate SORTKEY details (such as INTERLEAVED / COMPOUND) etc. when using Describe Table.

Update (15th Sep 2017):
This project has now been named PsqlForks!

12 Aug 2017

Redshift support for psql

Am sure you know that psql doesn't go out of it's way to support Postgres' forks natively. I obviously understand the reasoning, which allowed me to find a gap that I could fill here.

The existing features (in psql) that work with any Postgres fork (like Redshift) are entirely because it is a fork of Postgres. Since I use psql heavily at work, last week I decided to begin maintaining a Postgres fork that better supports (Postgres forks, but initially) Redshift. As always, unless explicitly mentioned, this is entirely an unofficial effort.

The 'redshift' branch of this Postgres code-base, is aimed at supporting Redshift in many ways:
  • Support Redshift related artifacts
    • Redshift specific SQL Commands / variations
    • Redshift Libraries
  • Support AWS specific artifacts
  • Support Redshift specific changes
    • For e.g. "/d table" etc.

The idea is:
  • Maintain this branch for the long-term
    • At least as long as I have an accessible Redshift cluster
  • Down the line look at whether other Postgres forks (for e.g. RDS Postgres) need such special attention
    • Although nothing much stands out yet
      • Except some rare exceptions like this or this, which do need to go through an arduous long wait / process of refinement.
  • Change the default port to 5439 (or whatever the flavour supports)
    • ...with an evil grin ;)
  • Additionally, as far as possible:
    • Keep submitting Postgres related patches back to Postgres master
    • Keep this branch up to date with Postgres master

Update (31st August 2017)
  • Currently this branch supports most Redshift specific SQL commands such as
    • CREATE LIBRARY
    • CREATE TABLE (DISTKEY / DISTSTYLE / ...)
    • Returns non-SQL items like
      • ENCODINGs (a.k.a. Compressions like ZSTD / LZO etc )
      • REGIONs (for e.g. US-EAST-1 etc.)
  • Of course some complex variants (for e.g. GRANT SELECT, UPDATE ON ALL TABLES IN SCHEMA TO GROUP xxx ) don't automatically come up with tab-complete feature. This is primarily because psql's tab-complete feature isn't very powerful to cater to all such scenarios which in turn is because psql's auto-complete isn't a full-fledged parser to begin with.
  • In a nutshell, this branch is now in a pretty good shape to auto-complete the most common Redshift specific SQL Syntax.
  • The best part is that this still merges perfectly with Postgres mainline!

    Let me know if you find anything that needs inclusion, or if I missed something.

    ====================================

    $  psql -U redshift_user -h localhost -E -p 5439 db
    psql (client-version:11devel, server-version:8.0.2, engine:redshift)
    Type "help" for help.

    db=#

    3 Aug 2017

    Reducing Wires

    Recently got an additional monitor for my workstation@home and found that the following wires were indispensable:

    • USB Mouse
    • Monitor VGA / HDMI / DVI cable
    • USB Hub cable (Pen Drive etc.)
    I was lucky that this ($20 + used) Dell monitor was an awesome buy since it came with a Monitor USB Hub (besides other goodies such as vertical rotate etc).

    After a bit of rejigging, this is how things finally panned-out:
    • 1 USB Wire (from the laptop) for the MUH (Monitor USB Hub)
      • This is usually something like this.
    • Use a USB->DVI converter and use that to connect MUH -> Monitor DVI port
      • This is usually something like this.
    • Plug USB Mouse to MUH
    • With things working so well, I also plugged a Wireless Touchpad dongle to the MUH
    So now when I need to do some office work, connecting 1 USB wire gets me up and running!

    #LoveOneWires :)

    Now only if I could find a stable / foolproof Wireless solution here ;)