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Row Number vs Row ID
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Row Number vs Row ID

MediumSQL · PostgreSQL

Problem

Explain the difference between ROW_NUMBER and ROWID in Oracle and when you would use each.

Using PostgreSQL, write a query that demonstrates the logical row sequence produced by ROW_NUMBER(). Explain why Oracle ROWID has no direct PostgreSQL equivalent, and identify the closest PostgreSQL physical tuple identifier.

Output

  1. One row per ledger entry with account_id, entry_id, entry_date, and row_number
  2. Assign sequence numbers independently within each account by date, with entry_id as the tie-breaker
  3. Sort by account, date, and entry ID

Schema

ledger_entries
ColumnTypeDescription
entry_idPKINTStable primary key for the ledger entry
account_idVARCHAR(20)Account associated with the entry
entry_dateDATEBusiness date of the ledger entry
entry_typeVARCHAR(30)Type of ledger activity
amountNUMERIC(12,2)Signed amount recorded for the entry
descriptionTEXTOptional entry description
Tablesledger_entries
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