Re: Should I add a Index Key in this case ?
Rob Sargent <[email protected]> Wed, 16 Oct 2019 10:05:26 -0600
| Newsgroups | gmane.comp.db.postgresql.sql |
|---|---|
| Message-ID | <[email protected]> |
--Apple-Mail=_B818D664-3AB3-4B41-A5EA-7E86C0CAE55B Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Oct 16, 2019, at 9:47 AM, Karen Goh <[email protected]> wrote: >=20 > Hi Steve, >=20 > My question is should I use index on the Seat_Viewing_id ? >=20 > I have no experience in using Index hence I asked if it should be made = auto-incremental? >=20 > Kindly advise how should I alter my existing table to have index.=20 >=20 > Tks! >=20 alter table doc here: = https://www.postgresql.org/docs/10/sql-altertable.html = <https://www.postgresql.org/docs/10/sql-altertable.html> you will likely need an index on that new column, though it=E2=80=99s = not clear to how you wish to fill in the value for existing rows. = Perhaps you should share your current table definition? I think you may need a seat_viewing table, in which you place the id of = the viewed seats. You would want a unique index on the new table using = the existing seat id but you do NOT want the column to be of type = serial, just (big?) integer. --Apple-Mail=_B818D664-3AB3-4B41-A5EA-7E86C0CAE55B Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8 <html><head><meta http-equiv=3D"Content-Type" content=3D"text/html; = charset=3Dutf-8"></head><body style=3D"word-wrap: break-word; = -webkit-nbsp-mode: space; line-break: after-white-space;" class=3D""><br = class=3D""><div><br class=3D""><blockquote type=3D"cite" class=3D""><div = class=3D"">On Oct 16, 2019, at 9:47 AM, Karen Goh <<a = href=3D"mailto:[email protected]" = class=3D"">[email protected]</a>> wrote:</div><br = class=3D"Apple-interchange-newline"><div class=3D""><!--[if gte mso = 9]><xml><o:OfficeDocumentSettings><o:AllowPNG/><o:PixelsPerInch>96</o:Pixe= lsPerInch></o:OfficeDocumentSettings></xml><![endif]--><div class=3D""> Hi Steve,<div class=3D""><br class=3D""></div><div class=3D"">My = question is should I use index on the Seat_Viewing_id ?</div><div = class=3D""><br class=3D""></div><div class=3D"">I have no experience in = using Index hence I asked if it should be made = auto-incremental?</div><div class=3D""><br class=3D""></div><div = class=3D"">Kindly advise how should I alter my existing table to have = index. </div><div class=3D""><br class=3D""></div><div = class=3D"">Tks!<br class=3D""><br = class=3D""></div></div></div></blockquote>alter table doc here: <a = href=3D"https://www.postgresql.org/docs/10/sql-altertable.html" = class=3D"">https://www.postgresql.org/docs/10/sql-altertable.html</a><br = class=3D""></div><div>you will likely need an index on that new column, = though it=E2=80=99s not clear to how you wish to fill in the value for = existing rows. Perhaps you should share your current table = definition?</div><div>I think you may need a seat_viewing table, in = which you place the id of the viewed seats. You would want a = unique index on the new table using the existing seat id but you do NOT = want the column to be of type serial, just (big?) integer.</div><br = class=3D""></body></html>= --Apple-Mail=_B818D664-3AB3-4B41-A5EA-7E86C0CAE55B--