Given my query: ==================================================== SELECT "PrintSamples"."MachineID" , "PrintSamples"."PrintCopyID" , "tblColors"."Color" , "tblBlockAC"."AreaCoverage" , "tblFriendlyParameterNames"."FriendlyParameterName" AS "Measurement" , "ParameterValues"."ParameterValue" AS "Value" FROM "AnalysisModules" INNER JOIN (("tblBlockAC" INNER JOIN "Targets" ON "tblBlockAC"."TargetID" = "Targets"."TargetID") INNER JOIN (("tblColors" INNER JOIN ("tblTPNamesAndColors" INNER JOIN "PrintSamples" ON "tblTPNamesAndColors"."TestPatternName" = "PrintSamples"."TestPatternName") ON "tblColors"."ColorID" = "tblTPNamesAndColors"."ColorID") INNER JOIN (("DigitalImages" INNER JOIN "PrintSampleAnalyses" ON "DigitalImages"."ImageID" = "PrintSampleAnalyses"."ImageID") INNER JOIN (("tblFriendlyParameterNames" INNER JOIN "ParameterNames" ON "tblFriendlyParameterNames"."ParameterID" = "ParameterNames"."ParameterID") INNER JOIN ("Measurements" INNER JOIN "ParameterValues" ON "Measurements"."MeasurementID" = "ParameterValues"."MeasurementID") ON "ParameterNames"."ParameterID" = "ParameterValues"."ParameterID") ON "PrintSampleAnalyses"."psaID" = "Measurements"."psaID") ON "PrintSamples"."PrintSampleID" = "DigitalImages"."PrintSampleID") ON "Targets"."TargetID" = "Measurements"."TargetID") ON "AnalysisModules"."MetricID" = "Measurements"."MetricID" WHERE (("PrintSamples"."MachineID" = '3179') AND (("AnalysisModules"."AnalysisModuleName")='DeltaE') AND (("PrintSamples"."TestPatternName") Like '%TP8%') AND (("ParameterNames"."ParameterName") Like 'Mean%')) ORDER BY "PrintSamples"."MachineID" , "PrintSamples"."PrintCopyID" , "tblBlockAC"."AreaCoverage" , "tblColors"."ColorID" , "tblFriendlyParameterNames"."FriendlyParameterName" ; My explain analyze output: ==================================================== QUERY PLAN Sort (cost=429075.71..429075.71 rows=2 width=45) (actual time=44984.000..44984.000 rows=2352 loops=1) Sort Key: "PrintSamples"."MachineID" -> Nested Loop (cost=415721.80..429075.70 rows=2 width=45) (actual time=44828.000..44968.000 rows=2352 loops=1) -> Nested Loop (cost=415721.80..429069.64 rows=2 width=53) (actual time=44828.000..44937.000 rows=2352 loops=1) -> Hash Join (cost=415721.80..429054.51 rows=5 width=45) (actual time=44828.000..44874.000 rows=2352 loops=1) Hash Cond: ("outer"."MetricID" = "inner"."MetricID") -> Hash Join (cost=415720.44..429052.95 rows=31 width=49) (actual time=44828.000..44874.000 rows=2352 loops=1) Hash Cond: ("outer"."PrintSampleID" = "inner"."PrintSampleID") -> Hash Join (cost=415665.42..428234.44 rows=152635 width=28) (actual time=35234.000..43656.000 rows=835385 loops=1) Hash Cond: ("outer"."psaID" = "inner"."psaID") -> Merge Join (cost=414212.50..424585.45 rows=146405 width=28) (actual time=35062.000..41235.000 rows=835385 loops=1) Merge Cond: ("outer"."MeasurementID" = "inner"."MeasurementID") -> Sort (cost=202227.03..202593.04 rows=146405 width=20) (actual time=27140.000..27451.000 rows=835385 loops=1) Sort Key: "ParameterValues"."MeasurementID" -> Hash Join (cost=3.23..189665.77 rows=146405 width=20) (actual time=15.000..25139.000 rows=835385 loops=1) Hash Cond: ("outer"."ParameterID" = "inner"."ParameterID") -> Seq Scan on "ParameterValues" (cost=0.00..143853.18 rows=8787918 width=12) (actual time=0.000..13302.000 rows=8787896 loops=1) -> Hash (cost=3.23..3.23 rows=1 width=20) (actual time=0.000..0.000 rows=0 loops=1) -> Hash Join (cost=1.62..3.23 rows=1 width=20) (actual time=0.000..0.000 rows=4 loops=1) Hash Cond: ("outer"."ParameterID" = "inner"."ParameterID") -> Seq Scan on "tblFriendlyParameterNames" (cost=0.00..1.40 rows=40 width=16) (actual time=0.000..0.000 rows=40 loops=1) -> Hash (cost=1.61..1.61 rows=1 width=4) (actual time=0.000..0.000 rows=0 loops=1) -> Seq Scan on "ParameterNames" (cost=0.00..1.61 rows=1 width=4) (actual time=0.000..0.000 rows=4 loops=1) Filter: (("ParameterName")::text ~~ 'Mean%'::text) -> Sort (cost=211985.47..216074.23 rows=1635502 width=16) (actual time=7922.000..9003.000 rows=2145644 loops=1) Sort Key: "Measurements"."MeasurementID" -> Seq Scan on "Measurements" (cost=0.00..43191.02 rows=1635502 width=16) (actual time=0.000..3598.000 rows=1635476 loops=1) -> Hash (cost=1403.55..1403.55 rows=19748 width=8) (actual time=157.000..157.000 rows=0 loops=1) -> Hash Join (cost=529.85..1403.55 rows=19748 width=8) (actual time=63.000..142.000 rows=19748 loops=1) Hash Cond: ("outer"."ImageID" = "inner"."ImageID") -> Seq Scan on "PrintSampleAnalyses" (cost=0.00..577.48 rows=19748 width=8) (actual time=0.000..16.000 rows=19748 loops=1) -> Hash (cost=480.48..480.48 rows=19748 width=8) (actual time=63.000..63.000 rows=0 loops=1) -> Seq Scan on "DigitalImages" (cost=0.00..480.48 rows=19748 width=8) (actual time=0.000..32.000 rows=19748 loops=1) -> Hash (cost=55.01..55.01 rows=4 width=29) (actual time=0.000..0.000 rows=0 loops=1) -> Hash Join (cost=53.33..55.01 rows=4 width=29) (actual time=0.000..0.000 rows=29 loops=1) Hash Cond: ("outer"."ColorID" = "inner"."ColorID") -> Hash Join (cost=52.28..53.90 rows=4 width=20) (actual time=0.000..0.000 rows=29 loops=1) Hash Cond: (("outer"."TestPatternName")::text = ("inner"."TestPatternName")::text) -> Seq Scan on "tblTPNamesAndColors" (cost=0.00..1.26 rows=26 width=29) (actual time=0.000..0.000 rows=26 loops=1) -> Hash (cost=52.27..52.27 rows=4 width=44) (actual time=0.000..0.000 rows=0 loops=1) -> Index Scan using "PSMachineID_idx" on "PrintSamples" (cost=0.00..52.27 rows=4 width=44) (actual time=0.000..0.000 rows=29 loops=1) Index Cond: (("MachineID")::text = '3179'::text) Filter: (("TestPatternName")::text ~~ '%TP8%'::text) -> Hash (cost=1.04..1.04 rows=4 width=13) (actual time=0.000..0.000 rows=0 loops=1) -> Seq Scan on "tblColors" (cost=0.00..1.04 rows=4 width=13) (actual time=0.000..0.000 rows=4 loops=1) -> Hash (cost=1.35..1.35 rows=4 width=4) (actual time=0.000..0.000 rows=0 loops=1) -> Seq Scan on "AnalysisModules" (cost=0.00..1.35 rows=4 width=4) (actual time=0.000..0.000 rows=3 loops=1) Filter: (("AnalysisModuleName")::text = 'DeltaE'::text) -> Index Scan using "tblBlockAC_pkey" on "tblBlockAC" (cost=0.00..3.01 rows=1 width=8) (actual time=0.013..0.013 rows=1 loops=2352) Index Cond: ("outer"."TargetID" = "tblBlockAC"."TargetID") -> Index Scan using "Targets_pkey" on "Targets" (cost=0.00..3.01 rows=1 width=4) (actual time=0.006..0.013 rows=1 loops=2352) Index Cond: ("Targets"."TargetID" = "outer"."TargetID") Total runtime: 45312.000 ms My indices: ==================================================== CREATE INDEX "PVMeasurementID_idx" ON "ParameterValues"("MeasurementID"); CREATE INDEX "PVParameterID_idx" ON "ParameterValues"("ParameterID"); CREATE INDEX "PSTestPatternName_idx" ON "PrintSamples"("TestPatternName"); CREATE INDEX "PSMachineID_idx" ON "PrintSamples"("MachineID"); CREATE INDEX "PSMachineIDTestPatternName_idx" ON "PrintSamples"("MachineID", "TestPatternName"); CREATE INDEX "DIPrintSampleID_idx" ON "DigitalImages"("PrintSampleID"); CREATE INDEX "PSAImageID_idx" ON "PrintSampleAnalyses"("ImageID"); CREATE INDEX "MpsaID_idx" ON "Measurements"("psaID"); CREATE INDEX "MMetricID_idx" ON "Measurements"("MetricID"); CREATE INDEX "MTargetID_idx" ON "Measurements"("TargetID"); CREATE INDEX "AMAnalysisModuleName_idx" ON "AnalysisModules"("AnalysisModuleName"); Why aren't more of my indices used? Especially "MpsaID_idx", "MMetricID_idx", "MTargetID_idx", "PVMeasurementID_idx" or "PVParameterID_idx". What am I missing? Mike ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq