On Wed, Dec 7, 2016 at 8:25 PM, Adrian Klaver <adrian.klaver@xxxxxxxxxxx> wrote:
On 12/07/2016 05:19 PM, metaresolve wrote:
Uh, yeah, it was a SELECT * from cc_20161207;
I know, it was dumb. I didn't realize it would break it or at least run for
a while. I tend to do things in small steps, run a query, check my results,
then tweak.
You're right, I wouldn't want to be viewing those million. so I guess I
could just be doing the top 10000 rows to get a sense, then be doing my
aggregate group bys/etc to get my final numbers? That's how I hacked Access
to be my data analysis program until I got to Alteryx. But I was also never
using files of 1M then.
FYI pgAdmin, if I remember correctly, has a setting that limits the maximum number of rows that it will fetch at a time.
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Adrian Klaver
adrian.klaver@xxxxxxxxxxx
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With regard to John's comments
>Postgres, on a properly scaled and tuned database server, can handle billions of records.
>Obviously, doing something silly like querying all billions at once will never be fast, thats a lot of data to marshal and process.
>Postgres, on a properly scaled and tuned database server, can handle billions of records.
>Obviously, doing something silly like querying all billions at once will never be fast, thats a lot of data to marshal and process.
On a similar note, your table structure is not exactly optimized for a relational database.
I see no primary key to identify each row. In addition, the election & vote columns
belong in a separate table that is a child of cc_20161207, since they are repeating fields.
eg:
ALTER TABLE cc_20161207
ADD COLUMN cc_20161207_pk serial;
UPDATE cc_20161207
SET cc_20161207_pk = nextval(cc_20161207_pk_seq)
WHERE cc_20161207_pk IS NULL;
ALTER TABLE cc_20161207
ALTER COLUMN cc_20161207_pk SET NOT NULL;
ALTER TABLE cc_20161207
ADD CONSTRAINT cc_20161207 PRIMARY KEY (cc_20161207_pk);
CREATE TABLE election_data (
cc_20161207_pk bigint NOT NULL,
election_id serial NOT NULL,
election varchar(4),
vote_type varchar(1)
CONSTRAINT election_data_pk PRIMARY KEY (cc_20161207_pk, election_id)
);
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Melvin Davidson
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.![]()
I reserve the right to fantasize. Whether or not you
wish to share my fantasy is entirely up to you.
