SQL · Theory

Sharding

Theory

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Sharding

Sharding is a SQL idea you prove with Sharding on Riya's board, not with a slogan.

Sharding on the board: one Sharding step Riya can write from memory. Then say what Sharding on Riya's board looks like after.

Without Sharding, a viva board gets messy and Sharding on Riya's board is hard to trust.

Use Sharding when Sharding on Riya's board must stay clear. If a simpler SQL step works, use that instead.

If Sharding on Riya's board breaks under Sharding, check copy-pasting Sharding without a dry-run first.

Place Sharding next to nearby SQL work — one Sharding step Riya can write from memory is the link.

Close Sharding with: “If I skip it, Sharding on Riya's board goes wrong like this: copy-pasting Sharding without a dry-run.”

Exam tip

Board: Sharding on Riya's board. Dry-run Sharding. Name the trap: copy-pasting Sharding without a dry-run.

Sharding — sample query

-- Sharding
CREATE TABLE demo (
  id INTEGER PRIMARY KEY,
  label TEXT NOT NULL,
  qty INTEGER DEFAULT 0
);
INSERT INTO demo (id, label, qty) VALUES
  (1, 'alpha', 2),
  (2, 'beta', 5);
SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

Sharding: create two demo rows, then SELECT qty >= 2 ordered. Say which labels come back.

Short notes

DefSharding — Riya uses it for Sharding on Riya's board in a viva board.
RuleSharding → one Sharding step Riya can write from memory.
RememberSharding + InnoDB (a viva board).
UseSharding in a viva board (Sharding on Riya's board).
TrapSharding — copy-pasting Sharding without a dry-run.
ExSharding → Sharding on Riya's board.

-- Sharding CREATE TABLE demo ( id INTEGER PRIMARY KEY, label TEXT NOT NULL, qty INTEGER DEFAULT 0 ); INSERT INTO demo (id, label, qty) VALUES (1, 'alpha', 2), (2, 'beta', 5); SELECT label, qty FROM demo WHERE qty >= 2 ORDER BY qty DESC;

Sharding

Sharding — sample query

Short notes

Questions

Sharding

Sharding — sample query

Short notes

Questions