mattrco’s gists

mattrco / VdbeIntExtract.h

Created October 10, 2012 19:33

Selected attributes of struct Vdbe from VdbeInt.h

	struct Vdbe {
	sqlite3 db; / The database connection that owns this statement */
	Op aOp; / Space to hold the virtual machine's program */
	Mem aMem; / The memory locations */
	Mem *apArg; / Arguments to currently executing user function */
	Mem aColName; / Column names to return */
	Mem pResultSet; / Pointer to an array of results */
	int nMem; /* Number of memory locations currently allocated */
	int nOp; /* Number of instructions in the program */
	VdbeCursor *apCsr; / One element of this array for each open cursor */

mattrco / insert.log

Created October 10, 2012 19:39

Example SQLite INSERT

+sqlite> .schema names
+CREATE TABLE names(id int, name string);
+sqlite> INSERT INTO names VALUES (1, 'Holly');
+sqlite> SELECT * FROM names;
+|  Holly

mattrco / explain.log

Created October 10, 2012 19:52

SQLite Explain Insert

	sqlite> EXPLAIN INSERT INTO names VALUES (1, 'Holly');
	addr opcode p1 p2 p3 p4 p5 comment
	---- ------------- ---- ---- ---- ------------- -- -------------
	0 Trace 0 0 0 00
	1 Goto 0 10 0 00 Jump to address P2 (line 10 here, so starts transaction)
	2 OpenWrite 0 2 0 2 00 Open a read/write cursor (only one permitted)
	3 NewRowid 0 1 0 00 Record number, in this case specified in our INSERT statement
	4 Integer 1 2 0 00
	5 String8 0 3 0 Holly 00
	6 MakeRecord 2 2 4 dc 00 Convert P2 registers beginning from P1 into a database record

mattrco / index.log

Created October 10, 2012 20:02

VDBE opcodes for adding an index to an integer column

	sqlite> EXPLAIN CREATE INDEX IF NOT EXISTS exampleidx ON names (id);
	addr opcode p1 p2 p3 p4 p5 comment
	---- ------------- ---- ---- ---- ------------- -- -------------
	0 Trace 0 0 0 00
	1 Goto 0 34 0 00
	2 CreateIndex 0 1 0 00
	3 OpenWrite 0 1 0 5 00
	4 NewRowid 0 2 0 00
	5 String8 0 3 0 index 00
	6 String8 0 4 0 exampleidx 00

mattrco / config.toml

Created June 29, 2014 12:18

Heka syslog -> file output

mattrco / mac-network-commands-terminal

Created April 19, 2020 19:37 — forked from jjnilton/mac-network-commands-cheat-sheet.md

	Mac Network Commands Cheat Sheet

	After writing up the presentation for MacSysAdmin in Sweden, I decided to go ahead and throw these into a quick cheat sheet for anyone who’d like to have them all in one place. Good luck out there, and stay salty.

	Get an ip address for en0:

	ipconfig getifaddr en0

	Same thing, but setting and echoing a variable:

	struct Vdbe {
	sqlite3 db; / The database connection that owns this statement */
	Op aOp; / Space to hold the virtual machine's program */
	Mem aMem; / The memory locations */
	Mem *apArg; / Arguments to currently executing user function */
	Mem aColName; / Column names to return */
	Mem pResultSet; / Pointer to an array of results */
	int nMem; /* Number of memory locations currently allocated */
	int nOp; /* Number of instructions in the program */
	VdbeCursor *apCsr; / One element of this array for each open cursor */

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