-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

{| |- ! Transaction Op !! t !! s !! Memory A !! Disk A!! Memory B !! Disk B !! Log |- | || || || || 3 || || 4 || <Start T> |- | I(A) || || || 3 || 3 || || 4 || |- | R(A,s) || || 3 || 3 || 3 || || 4 || |- | s:=s + 4 || || 7 || 3 || 3 || || 4 || |- | W(A,s) || || 7 || 7 || 3 || || 4 || |- | FLUSH LOG || || 7 || 7 || 3 || || 4 || <T, A, 3> |- | I(B) || || 7 || 7 || 3 || 4 || 4 || |- | R(B,t) || 4 || 7 || 7 || 3 || 4 || 4 || |- | t:= t*s || 28 || 7 || 7 || 3 || 4 || 4 || |- | W(B,t) || 28 || 7 || 7 || 3 || 28 || 4 || |- | FLUSH LOG || 28 || 7 || 7 || 3 || 28 || 4 || <T, B, 4> |- | O(A) || 28 || 7 || 7 || 7 || 28 || 4 || |- | O(B) || 28 || 7 || 7 || 7 || 28 || 28 || |- | || || || || || || || <Commit T> |}

-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

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-- Mar 25 In-Class Exercise

	I(A),  R(A,s), s:=s + 4, W(A,s),  FLUSH LOG, I(B), R(B,t), t:= t*s, W(B,t), FLUSH LOG, O(A), O(B)

Given: <pre> I(A), R(A,s), s:=s + 4, W(A,s), FLUSH LOG, I(B), R(B,t), t:= t*s, W(B,t), FLUSH LOG, O(A), O(B) </pre> Log record trace: {| |- !Transaction Op !! Value t !! Value s !! Memory Value A !! Disk Value A !! Memory Value B !! Disk Value B !! Log Records | || || || || || || || < START T > |- | I(A) || || || 3 || 3 || || 4 || N/A |- | R(A,s) || || 3 || 3 || 3 || || 4 || N/A |- | s:=s+4 || || 7 || 3 || 3 || || 4 || N/A |- | W(A,s) || || 7 || 7 || 3 || || 4 || < T, A, 3 > |- | FLUSH LOG || || 7 || 7 || 3 || || 4 || N/A |- | I(B) || || 7 || 7 || 3 || 4 || 4 || N/A |- | R(B,t) || 4 || 7 || 7 || 3 || 4 || 4 || N/A |- | t := t*s || 28 || 7 || 7 || 3 || 4 || 4 || N/A |- | W(B, t) || 28 || 7 || 7 || 3 || 28 || 4 || < T, B, 4 > |- | FLUSH LOG || 28 || 7 || 7 || 3 || 28 || 4 || N/A |- | O(A) || 28 || 7 || 7 || 7 || 28 || 4 || N/A |- | O(B) || 28 || 7 || 7 || 7 || 28 || 28 || N/A |- | || || || || || || || <COMMIT> |- | FLUSH LOG || || || || || || || |}

-- Mar 25 In-Class Exercise

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