Table Writes

Insert a New Row

INSERT adds a row when the key is new.

highlighted = computed this step

Insert a new row

INSERT adds a row when its key is not already present.

new key can be inserted\text{new key can be inserted}

Apply the insert

The write applies 1 time, and final rows become 4.

final rows=4\text{final rows}=4

Write examples are tiny finite row modifications; SQL dialects, transactions, constraints beyond the visible key, triggers, indexes, concurrency, performance, and product behavior are out of scope.

Insert a new row: base tableidnamepoints1Ada102Ben203Cy15 writes in orderstepkindkeydetail0insert4[4, Dee, 12] write resultsstepkindkeystatusreasonbeforeafter0insert4appliedok34 final tableidnamepoints1Ada102Ben203Cy154Dee12 write factsfactvaluebaseRowCount3writeCount1appliedCount1rejectedCount0finalRowCount4keyColumnidrowOrderkey

Read the final table

The inserted row appears in key order with the existing rows.

new row is visible\text{new row is visible}

Summary

The final table is recomputed from the base table plus the write.

recomputed final rows\text{recomputed final rows}