Except that should be for the header bytes only. It is somewhat inaccurate because IEEE doubles may be stored as varints and values 0 and 1 may be stored as just the header code 8 or 9 without storing the actual varint (if the schema version is 4 or more, which cannot be read in an extension, though I suppose the context points to the connection which points to the schema which somewhere along the way will have the schema version, though those pointers are supposed to be opaque). Plus of course that size is the size of the header + the size of the varint storing the size of the header all as a varint ...
However, assuming schema type 4 then the following is more accurate. Though if the column has no affinity then not all the optimizations are applied. SQLITE_PRIVATE void _recSizeFunc(sqlite3_context *context, int argc, sqlite3_value **argv) { sqlite_int64 hdrsize = 0; sqlite_int64 datsize = 0; sqlite_int64 sz; double v; int i; for (i=0; i<argc; i++) { switch (sqlite3_value_type(argv[i])) { case SQLITE_NULL: hdrsize += 1; break; case SQLITE_INTEGER: hdrsize += 1; sz = sqlite3_value_int64(argv[i]); if ((sz < 0) || (sz > 1)) datsize += _varIntSize_(sqlite3_value_int64(argv[i])); break; case SQLITE_FLOAT: hdrsize += 1; v = sqlite3_value_double(argv[i]); if ((fabs(v) <= 140737488355327.0) && (trunc(v) == v)) { if ((v < 0) || (v > 1)) datsize += _varIntSize_((sqlite_int64)v); } else datsize += 8; break; case SQLITE_TEXT: sqlite3_value_blob(argv[i]); sz = sqlite3_value_bytes(argv[i]); hdrsize += _varIntSize_(sz*2+12); datsize += sz; break; case SQLITE_BLOB: sz = sqlite3_value_bytes(argv[i]); hdrsize += _varIntSize_(sz*2+13); datsize += sz; break; } } sqlite3_result_int64(context, _varIntSize_(hdrsize +_varIntSize_(hdrsize)) + hdrsize + datsize); } -- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume. >-----Original Message----- >From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> On >Behalf Of Hick Gunter >Sent: Monday, 27 January, 2020 05:32 >To: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> >Subject: Re: [sqlite] [EXTERNAL] Re: Row length in SQLITE > >You are missing > >maxsize += _varIntSize_(maxsize) > >fort he size varint at the begin oft he header just before the return > >-----Ursprüngliche Nachricht----- >Von: sqlite-users [mailto:sqlite-users-boun...@mailinglists.sqlite.org] >Im Auftrag von Keith Medcalf >Gesendet: Montag, 27. Januar 2020 12:43 >An: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> >Betreff: [EXTERNAL] Re: [sqlite] Row length in SQLITE > > >Here is a wee bit of C code that you can compile as a plugin that will >give you the row size (well, it may be bigger than the actual record size >by a few bytes but it is pretty close) ... > >works properly for utf-16 encoded databases as well. > >-----//----- sqlsize.c -----//----- >#include "sqlite3ext.h" >SQLITE_EXTENSION_INIT1 > >#ifndef SQLITE_PRIVATE > #define SQLITE_PRIVATE static >#endif > >static inline sqlite_int64 _varIntSize_(sqlite_int64 v) { > sqlite_int64 uu; > > if (v<0) > uu = ~v; > else > uu = v; > if (uu <= 127 ) > return 1; > else if (uu <= 32767) > return 2; > else if (uu <= 8388607) > return 3; > else if (uu <= 2147483647) > return 4; > else if (uu <= 140737488355327LL) > return 6; > else return 8; >} > >SQLITE_PRIVATE void _recSizeFunc(sqlite3_context *context, int argc, >sqlite3_value **argv) { > sqlite_int64 maxsize = 0; > sqlite_int64 sz; > int i; > > for (i=0; i<argc; i++) > { > switch (sqlite3_value_type(argv[i])) > { > case SQLITE_NULL: > maxsize += 1; > break; > case SQLITE_INTEGER: > maxsize += _varIntSize_(sqlite3_value_int64(argv[i])) + >1; > break; > case SQLITE_FLOAT: > maxsize += 9; > break; > case SQLITE_TEXT: > sqlite3_value_blob(argv[i]); > sz = sqlite3_value_bytes(argv[i]); > maxsize += sz + _varIntSize_(sz*2+12); > break; > case SQLITE_BLOB: > sz = sqlite3_value_bytes(argv[i]); > maxsize += sz + _varIntSize_(sz*2+13); > break; > } > } > sqlite3_result_int64(context, maxsize); } > >#ifdef _WIN32 >#ifndef SQLITE_CORE >__declspec(dllexport) >#endif >#endif >int sqlite3_sqlsize_init(sqlite3 *db, char **pzErrMsg, const >sqlite3_api_routines *pApi) { > SQLITE_EXTENSION_INIT2(pApi); > > return sqlite3_create_function(db, "recsize", -1, >SQLITE_ANY|SQLITE_DETERMINISTIC|SQLITE_INNOCUOUS, 0, _recSizeFunc, 0, >0); } >-----//----- > >It is a bit of a PITA to call, but thats how the cookie crumbles ... > >>sqlite3 \data\apps\splunk\splunk.db >SQLite version 3.31.0 2020-01-27 11:17:22 Enter ".help" for usage hints. >sqlite> .schema details >CREATE TABLE Details >( > ApplianceID integer not null references Appliances(ApplianceID) >on delete cascade, > SrcIntID integer not null references Interfaces(InterfaceID) >on delete cascade, > DstIntID integer not null references Interfaces(InterfaceID) >on delete cascade, > Transport text not null collate nocase, > SrcHostID integer not null references Hosts(HostID) on delete >cascade, > SrcPort integer not null, > DstHostID integer not null references Hosts(HostID) on delete >cascade, > DstPort integer not null, > Action integer not null, > Count integer not null, > FileID integer not null references Files(FileID) on delete >cascade >); >sqlite> select _rowid_, recsize(ApplianceID, SrcIntID, DstIntID, >sqlite> Transport, SrcHostID, SrcPort, DstHostID, DstPort, Action, >sqlite> Count, FileID) from details limit 10; >1|27 >2|27 >3|27 >4|27 >5|27 >6|28 >7|27 >8|27 >9|28 >10|27 >sqlite> select max(recsize(ApplianceID, SrcIntID, DstIntID, Transport, >sqlite> SrcHostID, SrcPort, DstHostID, DstPort, Action, Count, FileID)) >sqlite> from details; >31 >sqlite> select avg(recsize(ApplianceID, SrcIntID, DstIntID, Transport, >sqlite> SrcHostID, SrcPort, DstHostID, DstPort, Action, Count, FileID)) >sqlite> from details; >29.4473800800817 >sqlite> select min(recsize(ApplianceID, SrcIntID, DstIntID, Transport, >sqlite> SrcHostID, SrcPort, DstHostID, DstPort, Action, Count, FileID)) >sqlite> from details; >26 >sqlite> select skew(recsize(ApplianceID, SrcIntID, DstIntID, Transport, >sqlite> SrcHostID, SrcPort, DstHostID, DstPort, Action, Count, FileID)) >sqlite> from details; >-0.378384651017371 >sqlite> select kurt(recsize(ApplianceID, SrcIntID, DstIntID, Transport, >sqlite> SrcHostID, SrcPort, DstHostID, DstPort, Action, Count, FileID)) >sqlite> from details; >0.130516904446944 > >-- >The fact that there's a Highway to Hell but only a Stairway to Heaven >says a lot about anticipated traffic volume. > >>-----Original Message----- >>From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> On >>Behalf Of Deon Brewis >>Sent: Friday, 24 January, 2020 21:14 >>To: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> >>Subject: Re: [sqlite] Row length in SQLITE >> >>No I mean e.g. >> >>row 1 = 500 bytes, >>row 2 = 600 bytes >>row 3 = 80 bytes >>row 4 = 300 bytes >> >>etc. >> >>Like the info that DBSTAT gives, but per row, not per page. This >>doesn't need to be performant - it's for usage analysis during >development time. >> >>- Deon >> >>-----Original Message----- >>From: sqlite-users <sqlite-users-boun...@mailinglists.sqlite.org> On >>Behalf Of Simon Slavin >>Sent: Wednesday, January 22, 2020 5:24 PM >>To: SQLite mailing list <sqlite-users@mailinglists.sqlite.org> >>Subject: Re: [sqlite] Row length in SQLITE >> >>On 22 Jan 2020, at 11:44pm, Deon Brewis <de...@outlook.com> wrote: >> >>> Is there any way to get the length of rows in a table / index in >>sqlite? >> >>Do you mean the count of rows in a table / index ? >> >> SELECT count(*) FROM MyTable >> >>There's no easy fast way to do this because SQLite doesn't keep that >>number handy anywhere. It stores the entries in a tree and it would >>have to manually count the leaves of the tree. >> >>---- >> >>Or do you mean the count of columns in a table / index ? >> >> SELECT * FROM MyTable LIMIT 1 >> >>and count the number of columns returned. Or in C >> >> sqlite3_column_count() >>_______________________________________________ >>sqlite-users mailing list >>sqlite-users@mailinglists.sqlite.org >>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >>_______________________________________________ >>sqlite-users mailing list >>sqlite-users@mailinglists.sqlite.org >>http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > >_______________________________________________ >sqlite-users mailing list >sqlite-users@mailinglists.sqlite.org >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > >___________________________________________ > Gunter Hick | Software Engineer | Scientific Games International GmbH | >Klitschgasse 2-4, A-1130 Vienna | FN 157284 a, HG Wien, DVR: 0430013 | >(O) +43 1 80100 - 0 > >May be privileged. May be confidential. Please delete if not the >addressee. >_______________________________________________ >sqlite-users mailing list >sqlite-users@mailinglists.sqlite.org >http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users