Re^2: Get all hash value into array

> I suggest "flattening" your hierarchical structure to a flat table.

Your approach implies that the data is essentially analog to a DB table. But you are losing the possibility to index the data by "zip" (?) or "state" with a hash lookup.

> Searching a table like that is simple,

I don't see why using 3 nested while each loops are more complicated. It's pretty generic and keeps all data available. (Though you have to take care not to mess up the each iterator)

> but does cost in performance because you have to examine each row for every search.

Hmm, if I wanted to represent a DB table I'd use an AoA with associated index hashes.

One at least for the columns aka fields.
Then one for each "unique" field holding the row indices.

I'm pretty sure this can already be found° on CPAN.

Probably as object or tied array.

I'm not very experienced with NoSQL but this might go into the same direction.

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery
FootballPerl is like chess, only without the dice}

°) a cursory look revealed Data::Table not sure if that's a good example though.

Comment on Re^2: Get all hash value into array

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Re^3: Get all hash value into array by Marshall (Canon) on Feb 13, 2020 at 08:43 UTC
Hi Rolf! Your approach implies that the data is essentially analog to a DB table. But you are losing the possibility to index the data by "zip" (?) or "state" with a hash lookup. My approach not only implies a "flat", "de-normalized" DB table, that is what it is. This will work great for a few ten's of thousands of lines. I am not "losing the possibility to index by "zip"". When you get to say 100,000K+ lines, then I would recommend a DB like SQLite. Let the DB take care of indexing. There are to be sure a lot of "if's, and's and but's" with a DB. However the OP's data structure does not appear to me to be efficient. From what I can tell, the use of the "zip" as a primary key doesn't make any sense. And the OP's hash structure is hard to search and inefficient. Yes, I do think that 1 loop is easier to understand than 3 loops. Cheers, Marshall	[reply]

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Re^3: Get all hash value into array
by Marshall (Canon) on Feb 13, 2020 at 08:43 UTC

Your approach implies that the data is essentially analog to a DB table.
But you are losing the possibility to index the data by "zip" (?) or "state" with a hash lookup.

My approach not only implies a "flat", "de-normalized" DB table, that is what it is. This will work great for a few ten's of thousands of lines. I am not "losing the possibility to index by "zip"". When you get to say 100,000K+ lines, then I would recommend a DB like SQLite. Let the DB take care of indexing. There are to be sure a lot of "if's, and's and but's" with a DB. However the OP's data structure does not appear to me to be efficient.

From what I can tell, the use of the "zip" as a primary key doesn't make any sense. And the OP's hash structure is hard to search and inefficient. Yes, I do think that 1 loop is easier to understand than 3 loops.
Cheers, Marshall

[reply]