---- SELECT---- btree index-- awk '{if($1<10){print;}else{next;}}' onek.data | sort +0n -1--SELECT onek.* WHERE onek.unique1 < 10   ORDER BY onek.unique1; unique1 | unique2 | two | four | ten | twenty | hundred | thousand | twothousand | fivethous | tenthous | odd | even | stringu1 | stringu2 | string4 ---------+---------+-----+------+-----+--------+---------+----------+-------------+-----------+----------+-----+------+----------+----------+---------       0 |     998 |   0 |    0 |   0 |      0 |       0 |        0 |           0 |         0 |        0 |   0 |    1 | AAAAAA   | KMBAAA   | OOOOxx       1 |     214 |   1 |    1 |   1 |      1 |       1 |        1 |           1 |         1 |        1 |   2 |    3 | BAAAAA   | GIAAAA   | OOOOxx       2 |     326 |   0 |    2 |   2 |      2 |       2 |        2 |           2 |         2 |        2 |   4 |    5 | CAAAAA   | OMAAAA   | OOOOxx       3 |     431 |   1 |    3 |   3 |      3 |       3 |        3 |           3 |         3 |        3 |   6 |    7 | DAAAAA   | PQAAAA   | VVVVxx       4 |     833 |   0 |    0 |   4 |      4 |       4 |        4 |           4 |         4 |        4 |   8 |    9 | EAAAAA   | BGBAAA   | HHHHxx       5 |     541 |   1 |    1 |   5 |      5 |       5 |        5 |           5 |         5 |        5 |  10 |   11 | FAAAAA   | VUAAAA   | HHHHxx       6 |     978 |   0 |    2 |   6 |      6 |       6 |        6 |           6 |         6 |        6 |  12 |   13 | GAAAAA   | QLBAAA   | OOOOxx       7 |     647 |   1 |    3 |   7 |      7 |       7 |        7 |           7 |         7 |        7 |  14 |   15 | HAAAAA   | XYAAAA   | VVVVxx       8 |     653 |   0 |    0 |   8 |      8 |       8 |        8 |           8 |         8 |        8 |  16 |   17 | IAAAAA   | DZAAAA   | HHHHxx       9 |      49 |   1 |    1 |   9 |      9 |       9 |        9 |           9 |         9 |        9 |  18 |   19 | JAAAAA   | XBAAAA   | HHHHxx(10 rows)---- awk '{if($1<20){print $1,$14;}else{next;}}' onek.data | sort +0nr -1--SELECT onek.unique1, onek.stringu1   WHERE onek.unique1 < 20    ORDER BY unique1 using >; unique1 | stringu1 ---------+----------      19 | TAAAAA      18 | SAAAAA      17 | RAAAAA      16 | QAAAAA      15 | PAAAAA      14 | OAAAAA      13 | NAAAAA      12 | MAAAAA      11 | LAAAAA      10 | KAAAAA       9 | JAAAAA       8 | IAAAAA       7 | HAAAAA       6 | GAAAAA       5 | FAAAAA       4 | EAAAAA       3 | DAAAAA       2 | CAAAAA       1 | BAAAAA       0 | AAAAAA(20 rows)---- awk '{if($1>980){print $1,$14;}else{next;}}' onek.data | sort +1d -2--SELECT onek.unique1, onek.stringu1   WHERE onek.unique1 > 980    ORDER BY stringu1 using <; unique1 | stringu1 ---------+----------     988 | AMAAAA     989 | BMAAAA     990 | CMAAAA     991 | DMAAAA     992 | EMAAAA     993 | FMAAAA     994 | GMAAAA     995 | HMAAAA     996 | IMAAAA     997 | JMAAAA     998 | KMAAAA     999 | LMAAAA     981 | TLAAAA     982 | ULAAAA     983 | VLAAAA     984 | WLAAAA     985 | XLAAAA     986 | YLAAAA     987 | ZLAAAA(19 rows)	---- awk '{if($1>980){print $1,$16;}else{next;}}' onek.data |-- sort +1d -2 +0nr -1--SELECT onek.unique1, onek.string4   WHERE onek.unique1 > 980    ORDER BY string4 using <, unique1 using >; unique1 | string4 ---------+---------     999 | AAAAxx     995 | AAAAxx     983 | AAAAxx     982 | AAAAxx     981 | AAAAxx     998 | HHHHxx     997 | HHHHxx     993 | HHHHxx     990 | HHHHxx     986 | HHHHxx     996 | OOOOxx     991 | OOOOxx     988 | OOOOxx     987 | OOOOxx     985 | OOOOxx     994 | VVVVxx     992 | VVVVxx     989 | VVVVxx     984 | VVVVxx(19 rows)	---- awk '{if($1>980){print $1,$16;}else{next;}}' onek.data |-- sort +1dr -2 +0n -1--SELECT onek.unique1, onek.string4   WHERE onek.unique1 > 980   ORDER BY string4 using >, unique1 using <; unique1 | string4 ---------+---------     984 | VVVVxx     989 | VVVVxx     992 | VVVVxx     994 | VVVVxx     985 | OOOOxx     987 | OOOOxx     988 | OOOOxx     991 | OOOOxx     996 | OOOOxx     986 | HHHHxx     990 | HHHHxx     993 | HHHHxx     997 | HHHHxx     998 | HHHHxx     981 | AAAAxx     982 | AAAAxx     983 | AAAAxx     995 | AAAAxx     999 | AAAAxx(19 rows)	---- awk '{if($1<20){print $1,$16;}else{next;}}' onek.data |-- sort +0nr -1 +1d -2--SELECT onek.unique1, onek.string4   WHERE onek.unique1 < 20   ORDER BY unique1 using >, string4 using <; unique1 | string4 ---------+---------      19 | OOOOxx      18 | VVVVxx      17 | HHHHxx      16 | OOOOxx      15 | VVVVxx      14 | AAAAxx      13 | OOOOxx      12 | AAAAxx      11 | OOOOxx      10 | AAAAxx       9 | HHHHxx       8 | HHHHxx       7 | VVVVxx       6 | OOOOxx       5 | HHHHxx       4 | HHHHxx       3 | VVVVxx       2 | OOOOxx       1 | OOOOxx       0 | OOOOxx(20 rows)---- awk '{if($1<20){print $1,$16;}else{next;}}' onek.data |-- sort +0n -1 +1dr -2--SELECT onek.unique1, onek.string4   WHERE onek.unique1 < 20    ORDER BY unique1 using <, string4 using >; unique1 | string4 ---------+---------       0 | OOOOxx       1 | OOOOxx       2 | OOOOxx       3 | VVVVxx       4 | HHHHxx       5 | HHHHxx       6 | OOOOxx       7 | VVVVxx       8 | HHHHxx       9 | HHHHxx      10 | AAAAxx      11 | OOOOxx      12 | AAAAxx      13 | OOOOxx      14 | AAAAxx      15 | VVVVxx      16 | OOOOxx      17 | HHHHxx      18 | VVVVxx      19 | OOOOxx(20 rows)---- test partial btree indexes---- As of 7.2, planner probably won't pick an indexscan without stats,-- so ANALYZE first.--ANALYZE onek2;---- awk '{if($1<10){print $0;}else{next;}}' onek.data | sort +0n -1--SELECT onek2.* WHERE onek2.unique1 < 10; unique1 | unique2 | two | four | ten | twenty | hundred | thousand | twothousand | fivethous | tenthous | odd | even | stringu1 | stringu2 | string4 ---------+---------+-----+------+-----+--------+---------+----------+-------------+-----------+----------+-----+------+----------+----------+---------       0 |     998 |   0 |    0 |   0 |      0 |       0 |        0 |           0 |         0 |        0 |   0 |    1 | AAAAAA   | KMBAAA   | OOOOxx       1 |     214 |   1 |    1 |   1 |      1 |       1 |        1 |           1 |         1 |        1 |   2 |    3 | BAAAAA   | GIAAAA   | OOOOxx       2 |     326 |   0 |    2 |   2 |      2 |       2 |        2 |           2 |         2 |        2 |   4 |    5 | CAAAAA   | OMAAAA   | OOOOxx       3 |     431 |   1 |    3 |   3 |      3 |       3 |        3 |           3 |         3 |        3 |   6 |    7 | DAAAAA   | PQAAAA   | VVVVxx       4 |     833 |   0 |    0 |   4 |      4 |       4 |        4 |           4 |         4 |        4 |   8 |    9 | EAAAAA   | BGBAAA   | HHHHxx       5 |     541 |   1 |    1 |   5 |      5 |       5 |        5 |           5 |         5 |        5 |  10 |   11 | FAAAAA   | VUAAAA   | HHHHxx       6 |     978 |   0 |    2 |   6 |      6 |       6 |        6 |           6 |         6 |        6 |  12 |   13 | GAAAAA   | QLBAAA   | OOOOxx       7 |     647 |   1 |    3 |   7 |      7 |       7 |        7 |           7 |         7 |        7 |  14 |   15 | HAAAAA   | XYAAAA   | VVVVxx       8 |     653 |   0 |    0 |   8 |      8 |       8 |        8 |           8 |         8 |        8 |  16 |   17 | IAAAAA   | DZAAAA   | HHHHxx       9 |      49 |   1 |    1 |   9 |      9 |       9 |        9 |           9 |         9 |        9 |  18 |   19 | JAAAAA   | XBAAAA   | HHHHxx(10 rows)---- awk '{if($1<20){print $1,$14;}else{next;}}' onek.data | sort +0nr -1--SELECT onek2.unique1, onek2.stringu1    WHERE onek2.unique1 < 20     ORDER BY unique1 using >; unique1 | stringu1 ---------+----------      19 | TAAAAA      18 | SAAAAA      17 | RAAAAA      16 | QAAAAA      15 | PAAAAA      14 | OAAAAA      13 | NAAAAA      12 | MAAAAA      11 | LAAAAA      10 | KAAAAA       9 | JAAAAA       8 | IAAAAA       7 | HAAAAA       6 | GAAAAA       5 | FAAAAA       4 | EAAAAA       3 | DAAAAA       2 | CAAAAA       1 | BAAAAA       0 | AAAAAA(20 rows)---- awk '{if($1>980){print $1,$14;}else{next;}}' onek.data | sort +1d -2--SELECT onek2.unique1, onek2.stringu1   WHERE onek2.unique1 > 980; unique1 | stringu1 ---------+----------     981 | TLAAAA     982 | ULAAAA     983 | VLAAAA     984 | WLAAAA     985 | XLAAAA     986 | YLAAAA     987 | ZLAAAA     988 | AMAAAA     989 | BMAAAA     990 | CMAAAA     991 | DMAAAA     992 | EMAAAA     993 | FMAAAA     994 | GMAAAA     995 | HMAAAA     996 | IMAAAA     997 | JMAAAA     998 | KMAAAA     999 | LMAAAA(19 rows)SELECT two, stringu1, ten, string4   INTO TABLE tmp   FROM onek;---- awk '{print $1,$2;}' person.data |-- awk '{if(NF!=2){print $3,$2;}else{print;}}' - emp.data |-- awk '{if(NF!=2){print $3,$2;}else{print;}}' - student.data |-- awk 'BEGIN{FS="      ";}{if(NF!=2){print $4,$5;}else{print;}}' - stud_emp.data---- SELECT name, age FROM person*; ??? check if differentSELECT p.name, p.age FROM person* p;  name   | age ---------+----- mike    |  40 joe     |  20 sally   |  34 sandra  |  19 alex    |  30 sue     |  50 denise  |  24 sarah   |  88 teresa  |  38 nan     |  28 leah    |  68 wendy   |  78 melissa |  28 joan    |  18 mary    |   8 jane    |  58 liza    |  38 jean    |  28 jenifer |  38 juanita |  58 susan   |  78 zena    |  98 martie  |  88 chris   |  78 pat     |  18 zola    |  58 louise  |  98 edna    |  18 bertha  |  88 sumi    |  38 koko    |  88 gina    |  18 rean    |  48 sharon  |  78 paula   |  68 julie   |  68 belinda |  38 karen   |  48 carina  |  58 diane   |  18 esther  |  98 trudy   |  88 fanny   |   8 carmen  |  78 lita    |  25 pamela  |  48 sandy   |  38 trisha  |  88 vera    |  78 velma   |  68 sharon  |  25 sam     |  30 bill    |  20 fred    |  28 larry   |  60 jeff    |  23 cim     |  30 linda   |  19(58 rows)---- awk '{print $1,$2;}' person.data |-- awk '{if(NF!=2){print $3,$2;}else{print;}}' - emp.data |-- awk '{if(NF!=2){print $3,$2;}else{print;}}' - student.data |-- awk 'BEGIN{FS="      ";}{if(NF!=1){print $4,$5;}else{print;}}' - stud_emp.data |-- sort +1nr -2--SELECT p.name, p.age FROM person* p ORDER BY age using >, name;  name   | age ---------+----- esther  |  98 louise  |  98 zena    |  98 bertha  |  88 koko    |  88 martie  |  88 sarah   |  88 trisha  |  88 trudy   |  88 carmen  |  78 chris   |  78 sharon  |  78 susan   |  78 vera    |  78 wendy   |  78 julie   |  68 leah    |  68 paula   |  68 velma   |  68 larry   |  60 carina  |  58 jane    |  58 juanita |  58 zola    |  58 sue     |  50 karen   |  48 pamela  |  48 rean    |  48 mike    |  40 belinda |  38 jenifer |  38 liza    |  38 sandy   |  38 sumi    |  38 teresa  |  38 sally   |  34 alex    |  30 cim     |  30 sam     |  30 fred    |  28 jean    |  28 melissa |  28 nan     |  28 lita    |  25 sharon  |  25 denise  |  24 jeff    |  23 bill    |  20 joe     |  20 linda   |  19 sandra  |  19 diane   |  18 edna    |  18 gina    |  18 joan    |  18 pat     |  18 fanny   |   8 mary    |   8(58 rows)