who to check onstat -g ses "session-id" output (What is osenv)

Hi, I am quite new to informix I am unable to understand the output of onstat -g ses "sessionid" command .I am surprised to see that the osenv is very high compared to other process. did anybody has idea what is osenv is stands for ? ======================================================== IBM Informix Dynamic Server Version 9.40.UC2 -- On-Line -- Up 02:56:16 --61840 Kbytes session #RSAM total used dynamic id user tty pid hostname threads memory memory explain 15 informix - 20308 adolphus 1 6373376 6366912 off tid name rstcb flags curstk status 39 sqlexec 401d9e68 G-XPX-- 2840 cond wait(logbf1) Memory pools count 1 name class addr totalsize freesize #allocfrag #freefrag 15 V 40955020 6373376 6464 131497 14 name free used name free used overhead 0 1648 scb 0 96 opentable 0 4440 filetable 0 776 log 0 4208 temprec 0 1608 keys 0 160 gentcb 0 1224 ostcb 0 2728 sqscb 0 13776 sql 0 40 rdahead 0 120 hashfiletab 0 280 osenv 0 6333576 sqtcb 0 2024 fragman 0 208 sqscb info scb sqscb optofc pdqpriority sqlstats optcompind directives 40941088 40956018 0 0 0 2 1 Sess SQL Current Iso Lock SQL ISAM F.E. Id Stmt type Database Lvl Mode ERR ERR Vers Explain 15 - fpt CR Not Wait 0 0 9.03 Off ==================================================================